Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Don & Tys on December 02, 2011, 11:30:42 pm
Title: Another Bulkhead Separation Story Part II
Post by: Don & Tys on December 02, 2011, 11:30:42 pm
:o Today I started on my bulkhead repair project and am feeling a bit overwhelmed by the extent of what I found. I only found one rolok intact (I think think that the only reason was because its hole was stripped), with two others about 2/3rds- all on the street side. Most of the rest were the 4 or 5 thread versions. The only place where there isn't very noticeable separation is closest to street side. At the worst, it is separated by about 1/2". Looking at the structure from underneath the differential, I was amazed to see that all of that heavy steel that supports the drive train seems to stop at the bulkhead. I expected to see some of those heavy 1/4" thick beams going through the bulkhead towards the front just below the floor level. I know the construction is semi monocoque, but I am left wondering if that thin walled tubing is all that connects the back of the coach to the front! In any case, I am thinking od scraping my original plan which was a version of the usual, only drilling 3" access holes and then plugging them with some plugs I found. The reason I wantedntobgobwith the bigger holes is because I plan to make some rectangular washers that are about 3" X 1 1/2" X 1/4" to distribute the clamping force of the through bolts to the horizontal walls of the box tubing. Now I am thinking of cutting a strip of fiberglass all the way across the coach from th bulkhead to the next cross frame member. If I can get that piece off intact, I could replace and just add a seam. If not, maybe covering it with some stainless steel sheet metal and using the vertical roloks of the next cross member to fasten it. Also wondering what other's have done about the end roloks which seem to terminate in line with the longitudinal rake members along the sides of the service bays.
I would appreciate any suggestions or sharing of experience from those that have done this repair. Anybody else have that many failed bolts? Amazing that the fiberglass of the sides of the coach seems to be free of delamination... Thanks, Don
Title: Re: Another Bulkhead Separation Story Part II
Post by: Don Hay on December 03, 2011, 12:43:24 am
Don,
Go to Barry "Beam's" website. Bulkhead Separation (http://beamalarm.com/Documents/bulkhead_separation.html) He has some information (procedures and pictures) from others of us who had a similar experience. I had to drill 13 new holes for grade 8 hardened 3/8" X 3" through - bolts and washers and locking nuts. I also cut a 1" X 1/8" strip into 1" squares for washers to spread the compression forces over the surface of the box frame. I believe that Brett Wolfe has written an extensive description of the procedure. You have to use a lot of cutting oil, lots of pressure on the drill, and very slow drill speeds. You'll need several GOOD drill bits.
I went with the individual holes and plugged them, but I recall at least one other owner cut a strip similar to what you are thinking of doing.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Don & Tys on December 03, 2011, 01:28:31 am
Go to Barry "Beam's" website. He has some information (procedures and pictures) from others of us who had a similar experience. I had to drill 13 new holes for grade 8 hardened 3/8" X 3" through - bolts and washers and locking nuts. I also cut a 1" X 1/8" strip into 1" squares for washers to spread the compression forces over the surface of the box frame. I believe that Brett Wolfe has written an extensive description of the procedure. You have to use a lot of cutting oil, lots of pressure on the drill, and very slow drill speeds. You'll need several GOOD drill bits.
I went with the individual holes and plugged them, but I recall at least one other owner cut a strip similar to what you are thinking of doing.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Benjie Zeller on December 03, 2011, 02:07:59 am
REALLY hoping I don't have to deal with this immediately on the coach I'm about to purchase! Did some research on the issue and am now armed to go check it out tomorrow before I close. Not sure it will deter me, but will be good to know what I'm in for. Thanks for the coincidental timing of the post!
Title: Re: Another Bulkhead Separation Story Part II
Post by: wolfe10 on December 03, 2011, 09:45:17 am
Benjie,
All you need to determine if there is an issue and the extent of it is our eyeballs to tell you if there is separation and an Inch-Pound torque wrench to verify that not only are the heads of the bolts there, but that they are not broken 3-4 threads in where they enter the box beam.
See: Bulkhead Repair-- A Comprehensive Look (http://www.foreforums.com/index.php?topic=8645.0)
And, in a case like Don's, indeed, I would drill individual holes through the floor section and then use one sheet of FG across the whole area to seal it.
It also saves a lot of hard drilling if you can "thread on through" the broken bolts as I describe and then just slightly enlarge the hole vs drilling a brand new hole. Soaking with a good penetrating oil for a couple of days/couple of applications made that a fairly easy proposition. If you drill the bottom holes slightly off-center of the broken bolt, that hole would allow you to either use the original hole or "sister" it.
Brett
Brett
Title: Re: Another Bulkhead Separation Story Part II
Post by: travelite on December 03, 2011, 10:25:53 am
Does anyone have an engineering drawing of the chassis, particularly the basement structure, the rear sub-frame structure, and the engine cradle? There are lots of photos out there, but it's difficult to piece together how the complete structure is assembled.
David Brady '02 BlueBird Wanderlodge LXi
Title: Re: Another Bulkhead Separation Story Part II
Post by: Donmystic1 on December 03, 2011, 12:52:21 pm
Where is this problem area located? I will have to look for this problem when I go to check out any U295's for sale.
Title: Re: Another Bulkhead Separation Story Part II
Post by: PatC on December 03, 2011, 01:03:37 pm
Where is this problem area located? I will have to look for this problem when I go to check out any U295's for sale.
See my post above for a link to how to check. Then look at the photos/description in Pat's post.
Brett
Title: Re: Another Bulkhead Separation Story Part II
Post by: travelite on December 03, 2011, 02:07:40 pm
I haven't seen any mention of CorrosionX on this forum, but the bulkhead to rear subframe interface looks like a perfect application (NFI): CorrosionX Aviation (http://www.corrosionx.com/aviation.html) It sounds like a key part of any fix is removing all the rust at the interface. CorrosionX won't remove the rust. You'll need elbow grease and some kind of phosporic acid based rust converter for that.
David Brady '02 BlueBird Wanderlodge LXi, NC
Title: Re: Another Bulkhead Separation Story Part II
Post by: wolfe10 on December 03, 2011, 02:21:42 pm
David,
Really depends on how far this has been allowed to progress and also the cause.
My coach had a couple of broken bolts, no separation and no rust. I did undercoat the angle to make sure no moisture could migrate in through the bolt threads. No need for any corrosion block.
I have also seen coaches from up north (salt on roads) with rust jacking that would benefit from Corrosion X or painting or as I did, cleaning and undercoating.
Another cause of bulkhead separation is leaks into the wet bay that are allowed to remain unfixed for years. Eventually, the water standing in the back bay will find its way down and into the box beam area.
Bottom line, unless this is REALLY neglected, it is not a problem. Said another way, this starts with one broken Rolock bolt. That puts more load on those on either side of it and one of those lets go ................
My recommendation is to take the 10 minutes to put a torque wrench on the bolts once a year as part of your annual maintenance schedule. If a bad bolt is found, replace it.
And, as with any coach, if driven on salty roads, wash the underside. And don't allow leaks to leave water standing in the wet bay. Heck, one of the worst cases of bulkhead separation I ever saw was caused by a missing $05 gasket on the fresh water fill where the hose connects shore water. Allowed water to constantly leak into the wet bay.
This really isn't a big issue and does not affect a lot of coaches, but like any other maintenance item, if ignored/neglected, it can become more serious. NONE of these issues just "appear" with 15 broken bolts.
Brett
Title: Re: Another Bulkhead Separation Story Part II
Post by: Benjie Zeller on December 03, 2011, 02:30:32 pm
They're still doing some prep work on my coach to get it ready, but I went to check it out today. It's been raining for 3 days so I didn't get down on the ground or anything, but I could see that all the bolt heads are still there and there doesn't seem to be any separation. Hopefully we'll dry out by tomorrow and I'll be able to take a better look from under the coach to see if there is any separation and some pics.
I do have some questions some of you experts could maybe answer.
1. It seems this issue is pretty much inevitable at SOME point? If the Roloks are OK now, I'm wondering if I wouldn't just be better off backing each one out and then drilling the 3/8" hole instead of waiting for the problem to arise? If I wait until they break, am I not stuck then either drilling new holes or working on backing broken bolts out with Brett's method?
2. Has anyone considered replacing the current Roloks with larger 3/8 or 7/16 Roloks? In reading all the posts about bulkhead separation, it sounds like rust causes most of the issues one way or another (road salt, water in the bay, etc). If I replace with a larger, newer Rolok and seal, it should hold for another 20 years?
Thanks, Benjie
Title: Re: Another Bulkhead Separation Story Part II
Post by: Rudy on December 03, 2011, 02:31:43 pm
David,
CorrosionX is a great corrosion killing item that is also a wonderful lubricating and penetrating product. The key here is a product for killing corrosion on surfaces that you do not wish to paint. Control boards and electrical connections are examples.
In the bulkhead application, CorrosionX would need to be applied twice a year to maintain protection. The two year longevity in treating aircraft internal surfaces is that long because those surfaces are not open to the elements as is the bulkhead.
The bulkhead is an area that paint is the longer lasting solution so the corrosion killing product for this application is Ospho. Ospho is a dilute solution of phosphoric acid that is sold in most hardware and big box stores. Some stores do not carry the brand name Ospho but have the same thing by another brand.
Ospho chemically reacts with the ferrous oxide and changes it to ferrous phosphate, an inert salt. Once dry, the surface is primed and ready for paint to create long lasting protection. In cool or damp conditions, a hair dryer or heat gun can be used to accelerate drying.
I use CorrosionX on lots of things and like it a lot. If you search the forum, you will find posts on CorrosionX but none recently since I have seen you join the forum. Welcome by the way.
Hope this helps.
Title: Re: Another Bulkhead Separation Story Part II
Post by: wolfe10 on December 03, 2011, 02:37:08 pm
They're still doing some prep work on my coach to get it ready, but I went to check it out today. It's been raining for 3 days so I didn't get down on the ground or anything, but I could see that all the bolt heads are still there and there doesn't seem to be any separation. Hopefully we'll dry out by tomorrow and I'll be able to take a better look from under the coach to see if there is any separation and some pics.
I do have some questions some of you experts could maybe answer.
1. It seems this issue is pretty much inevitable at SOME point? If the Roloks are OK now, I'm wondering if I wouldn't just be better off backing each one out and then drilling the 3/8" hole instead of waiting for the problem to arise? If I wait until they break, am I not stuck then either drilling new holes or working on backing broken bolts out with Brett's method?
2. Has anyone considered replacing the current Roloks with larger 3/8 or 7/16 Roloks? In reading all the posts about bulkhead separation, it sounds like rust causes most of the issues one way or another (road salt, water in the bay, etc). If I replace with a larger, newer Rolok and seal, it should hold for another 20 years?
Thanks, Benjie
Benjie,
Unless caused by a water leak into the wet bay or by lots of corrosion from salt on roads, etc, this is NOT a wide spread issue.
On my coach with over 120,000 miles on it when I identified and repaired mine, 75% of the Rolocks were still in excellent shape.
But, do NOT, repeat do NOT just look at it. You need to apply torque to verify that that bolt head that looks just fine is not broken off 1/2 a thread into the box beam. The vast majority of broken bolts will appear just fine.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Benjie Zeller on December 03, 2011, 02:58:36 pm
Brett, understood. I was just commenting that it didn't look as obvious as some pics that I've seen. I plann on applying torque as soon as I can, but probably won't be until I get it home. Did you replace the 75% that weren't bad or leave them?
<><<><<><<><<>< benjie.zeller@gmail.com
512-587-4628
<><<><<><<><<><
Title: Re: Another Bulkhead Separation Story Part II
Post by: travelite on December 03, 2011, 03:06:34 pm
Hi Rudy,
That's good stuff, thanks for the clarification, and thank you for the welcome. Another great product, and I'm sure one that has been mentioned on this forum, is POR15. This product comes with Marine Clean (an alkaline cleaner), Metal Ready (a phosporic acid based etching, rust converting, and zinc phosphate primer), and POR15 (which I believe is an epoxy paint). I've had great success with it in these kinds of applications. Concerning CorrosionX, I'd be tempted to rig up a small diameter tube and a garden pump mechanism to coat the inside of the 1.5x1.5x0.125" box tubing. (But, that would certainly be overkill).
You guys clearly have this under control. I read thru the Beam pages so am kinda up to speed on the problem and the fix. There's not much more to add other than minor variances in the details of the fix which are really just personal preference; i.e., we all have our own quirks on how we like to tackle these kinds of projects. I won't bore you with mine! :)
Oh, one more thing. I don't know how many of your members have experience with the Fein Saw (NFI), but this is another indispensable tool for the RV owner: Amazon.com: Fein FMM 250Q Top Plus MultiMaster Oscillating Detail Sander Tool (http://www.amazon.com/Fein-FMM-250Q-Top-Plus/dp/B003INE4OY/ref=dp_ob_title_hi) . A tool like this would easily cut into the fiberglass basement layer, and make quick work of removing the foam to gain access to the inside of the box section.
Brent, I totally understand and agree with what you're saying. An owner may choose to be reactive or proactive. In either case, annual inspection of the bulkhead interface is a smart thing to do. If reactive, then based on these inspections one can take action. If proactive, then there's certainly nothing wrong with the peace of mind gained by knowing that you've already made the repairs, removed the rust, and treated the metal to add another 20 years of trouble free service.
David Brady '02 BlueBird, Wanderlodge LXi NC
Title: Re: Another Bulkhead Separation Story Part II
Post by: wolfe10 on December 03, 2011, 03:49:51 pm
Did you replace the 75% that weren't bad or leave them?
Left them. If any show up as bad in the future, will replace them. One year after replacing the few broken ones, ZERO more failed to hold torque.
Brett
Title: Re: Another Bulkhead Separation Story Part II
Post by: Rudy on December 03, 2011, 04:03:59 pm
David,
As usual, with really good stuff such as the Fein Saw, the savings I would receive from Amazon is what I wanted to spend in the first place. You pay to play.
As to the garden sprayer for CorrosionX, you are almost there but CorrosionX in Dallas has already beat you to the punch. They make the applicator for "Fogging" (instead of "Spraying") CorrosionX onto the interior surfaces of Aircraft. Shop air pressure gives much better atomization vs a pump up garden sprayer.
So a stronger tank than a plastic garden sprayer, a nozzle for atomizing the CorrosionX and air from the coach's air system and your done.
Title: Re: Another Bulkhead Separation Story Part II
Post by: wolfe10 on December 03, 2011, 04:07:20 pm
A hole saw the diameter determined by the plug you will be using (unless you have a lot of them to replace and will use a sheet of FG instead of individual plugs) works just fine-- around $10.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Don & Tys on December 03, 2011, 05:29:42 pm
Since all of mine need replacing, a sheet of fiberglass or stainless seems the way to go. Awhile back, I had found a soucre of what looked like gelcoat that came in rolls or sheets, but I can't seem to come up with it now... I think it was probaly just fiber reinforced plastic, but it looked like a good option for what I am contemplating. Anybody know of sources for such things? I really want to avoid to a full on glass layup working over my head! Thanks, Don
A hole saw the diameter determined by the plug you will be using (unless you have a lot of them to replace and will use a sheet of FG instead of individual plugs) works just fine-- around $10.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Pierce & Gaylie Stewart on December 03, 2011, 06:59:19 pm
For the interior preservation of any kind of steel tubing like we have in our Foretravels, use linseed oil only. This is know as "tube oil" in the aviation industry. A few ounces added to the tube's interior (square, rectangular, or round are all called "tubing") will coat all surfaces from capillary action and will stop any further rust. Folker Aircraft went to a synthetic oil on their F27 aircraft. The failure of the synthetic cost Folker several hundred thousand dollars and generated an AD note on the engine mounts. See the article at: aircraft tube oil (http://www.mechanicsupport.com/aircraft_tube.html)
Pierce
Title: Re: Another Bulkhead Separation Story Part II
Post by: Peter & Beth on December 03, 2011, 07:27:02 pm
For the interior preservation of any kind of steel tubing like we have in our Foretravels, use linseed oil only. This is know as "tube oil" in the aviation industry. A few ounces added to the tube's interior (square, rectangular, or round are all called "tubing") will coat all surfaces from capillary action and will stop any further rust. Folker Aircraft went to a synthetic oil on their F27 aircraft. The failure of the synthetic cost Folker several hundred thousand dollars and generated an AD note on the engine mounts. See the article at: aircraft tube oil (http://www.mechanicsupport.com/aircraft_tube.html)
Pierce
Yup! The oil in oil based paint of highest quality is linseed oil. You can still get the boiled linseed oil to add to the paint as thinner.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Rudy on December 03, 2011, 07:58:11 pm
Don,
Call James Stallings at Xtreme for the sheet of white fiberglass. I believe he will know a source.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Rudy on December 03, 2011, 08:07:12 pm
Pierce & Peter,
Linseed oil was noted as controlling corrosion as early as 1826 according to the referenced article.
CorrosionX is a invention of the 20th century. It is a fluid thin film that has polar bonding technology. This means it does not coat over existing corrosion but rather penetrates the corrosion. Each molecule of the surface of the metal item will have a molecule of CorrosionX polar bonded to it having penetrated and releasing the corrosion from the surface.
CorrosionX meets Mil-C-81309E for use on all aircraft including many military aircraft. It is available from the GSA for government use.
Although CorrosionX is superior for corrosion, there are other excellent uses for linseed oil for which CorrosionX would not be appropriate.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Dave M (RIP) on December 03, 2011, 08:32:05 pm
Linseed oil, good grief, have not thought of linseed oil since sitting on a footlocker at Paris Island rubbing it on a new wood stock on my M1 Rifle, one of the requirements of the day as a jarhead recruit.
Title: Re: Another Bulkhead Separation Story Part II
Post by: travelite on December 03, 2011, 08:46:49 pm
Linseed oil was noted as controlling corrosion as early as 1826 according to the referenced article.
CorrosionX is a invention of the 20th century. It is a fluid thin film that has polar bonding technology. This means it does not coat over existing corrosion but rather penetrates the corrosion. Each molecule of the surface of the metal item will have a molecule of CorrosionX polar bonded to it having penetrated and releasing the corrosion from the surface.
CorrosionX meets Mil-C-81309E for use on all aircraft including many military aircraft. It is available from the GSA for government use.
Although CorrosionX is superior for corrosion, there are other excellent uses for linseed oil for which CorrosionX would not be appropriate.
I want to thank Rudy for his response. While linseed oil is marvelous stuff, it's hard to argue with molecular polar bonding.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Pierce & Gaylie Stewart on December 03, 2011, 09:01:19 pm
I'm sure that CorrosionX does work well, especially where you don't want to have to wipe the linseed oil off your hands. I am also sure that Folker Aircraft also researched corrosion protection before they started with their synthetic substitute. While linseed oil was brought into use back in the 1800's, it is still the preferred choice for homebuilt/experimental aircraft today in the 21st century. The airworthiness directive (AD note) was a 21st century fix for a 20th century choice that proved inadequate.
Here is the Poly-Fiber website describing the properties and installation instructions of "Tubeseal", a linseed oil product (REF: MIL. SPEC. L-21260) from Consolidated Aircraft Coatings. Poly-Fiber Aircraft Coatings - Tubeseal Internal Tubing Corrosion Inhibitor (http://www.polyfiber.com/products/tubesealinternaltubingcorrosioninhibitor.htm)
Whenever you go to an airshow and watch the experimental planes race or demonstrate aerobatic manuvers, you can be sure the majority are using linseed oil to protect their fuselage and engine mounts from rust and corrosion.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Rudy on December 03, 2011, 09:17:08 pm
Pierce,
Do you fly? I love planes and recently got to go to lunch in a Robertson R-44 copter. What a ride!
Linseed oil certainly is good for corrosion protection or it would have fallen out of use for that long ago.
But do remember the majority of RVers are not using Foretravels as their coach of choice. I do not plan to follow their lead here either.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Chuck Pearson on December 03, 2011, 09:34:07 pm
Art,
Grainger supply has the fiberglass sheets in a variety of sizes and thicknesses. Here's a tip that might help you if you want to just reuse your old panel and run a seam. The easy way to apply glass overhead without having to shave the resin hardened hair off your head later is to wet out your fiberglass-you can do multiple layers of mat at one time if you don't over catalyze-on a strip of saran wrap. Carefully pick up the saran wrap with glass on it and place it into position overhead. No muss, no fuss plus the plastic allows you to really smooth, compress and blend the new glass in. If you leave the saran wrap on until the resin kicks when you peel it off you will have a gloss finish.
Chuck
Title: Re: Another Bulkhead Separation Story Part II
Post by: Don & Tys on December 04, 2011, 12:27:14 am
Thanks for the suggestion... it appears I am going to need a fair amount of this stuff. I pulled up the streetside floor of the fresh water tank compartment only see a discouraging level of rust present. I believe I will need to replace some, if not most of the square tubing down there. I hope that is the extent of it. Goung to sleep now, and maybe when I wake up it will all have been just a bad dream:( Don
Grainger supply has the fiberglass sheets in a variety of sizes and thicknesses. Here's a tip that might help you if you want to just reuse your old panel and run a seam. The easy way to apply glass overhead without having to shave the resin hardened hair off your head later is to wet out your fiberglass-you can do multiple layers of mat at one time if you don't over catalyze-on a strip of saran wrap. Carefully pick up the saran wrap with glass on it and place it into position overhead. No muss, no fuss plus the plastic allows you to really smooth, compress and blend the new glass in. If you leave the saran wrap on until the resin kicks when you peel it off you will have a gloss finish.
Chuck
Title: Re: Another Bulkhead Separation Story Part II
Post by: Pierce & Gaylie Stewart on December 04, 2011, 01:22:31 am
Don,
Your new rig really looked perfect in the photos. I there a chance it went through any kind of flood? Does not sound like a California vehicle. History?
Photo of the damage possible?
If you can wait, I've got a Miller 200 wire feed here.
Pierce
Title: Re: Another Bulkhead Separation Story Part II
Post by: Chuck Pearson on December 04, 2011, 10:31:55 am
Quote
Thanks for the suggestion... it appears I am going to need a fair amount of this stuff. I pulled up the streetside floor of the fresh water tank compartment only see a discouraging level of rust present. I believe I will need to replace some, if not most of the square tubing down there. I hope that is the extent of it. Goung to sleep now, and maybe when I wake up it will all have been just a bad dream:( Don
Well, shoot.
Art, you may be privy to this info, but I have never read a good explanation of the structural design of the bulkheads/lower square tube frame. I would encourage you to do this before assuming the worst. While the sight of rust is discouraging, it's not necessarily a death sentence for the steel. I'd for sure want to know just what the structural function of the various components is before starting to repair/replace.
Many of the industrial grade conversion coatings and inhibitors require a heavy coat of rust and/or scale to work properly. Wire brushing/sanding limits your options for repair to paint or oil type coatings. Most designs are so overbuilt that they work exactly the same with half the structure removed. The goal here is probably not to build a new Foretravel.....
Chuck
Title: Re: Another Bulkhead Separation Story Part II
Post by: travelite on December 04, 2011, 11:33:29 am
It would be great to find some engineering drawings of the Travelride chassis. If we had that, it'd be a lot easier imagining the loads on the lower bulkhead. I'm sure there are plenty of engineers on this board willing to offer some insight into loadings and deflections. You might start with imagining the stresses on components in all the bending and torsional modes. Six degrees of freedom, bending moments on three axis and torsional moments on 3 axis. Something like the lower bulkhead might offer quite a bit of stiffness in torsion about the x-axis, x being along the length of the coach (front to back), y being transverse to the length (left side to right side) and z being thru the roof. Imagine holding the front axle and twisting the rear. I have hunch that this is the kind of motion the lower bulkhead helps resist, but it's just a hunch with a heap of speculation added in! :)
Title: Re: Another Bulkhead Separation Story Part II
Post by: Peter & Beth on December 04, 2011, 04:21:52 pm
I've come to the conclusion that the discussion in connection with bulkhead repairs is not centered around a design flaw in the semi-monocoque chassis but rather a selection of materials and the fact that proper drainage from inside the utility bays was not incorporated into the design. In addition, a routine inspection/maintenance procedure was never coming from the factory in a timely manner as in a technical bulletin to owners/repair shops so that 100% of the possible coaches out there could be well informed. With some coaxing from valuable members of this forum, Foretravel put out a white paper a few years ago, and it is availble to all on this forum.
In conclusion, the bulkhead issue is not a deal breaker for anyone. It just needs to be taken into consideration and well inspected and maintained on an annual basis to ensure the original design functions as intended.
Title: Re: Another Bulkhead Separation Story Part II
Post by: Don & Tys on December 04, 2011, 04:25:46 pm
Pierce,
I am pretty sure flooding wasn't involved... It seems to be only in the rear and I suspect the cause was similar to what Barry showed pictures of on the second page in this thread Making sure the fresh water tank is completely full (http://www.foreforums.com/index.php?topic=10840.25). So in short, I believe it is likely from the freshwater tank area, possibly leaky overflow connection or the like. My next move is to pull the water heater, pump, etc. out, disconnect and pull the freshwater tank out and inspect from above after removing the rest of the compartment floor under the those parts. Hopefully, some of that steel is intact and I can reinforce the area where the angle iron attaches, bolt it up from above after drilling from below, reinsulate and cover with fiberglass sheeting or the like. But that could change in light of what else I find. I need to know the truth of it, and then we can decide how to proceed. My son has welding skills and a wirefeed welder, but that is an awesome offer and I thank you for it! If we get up in your neck of the woods when you happen to be there, I would love to meet up in person and see your shop set up when you finish (if you don't mind playing tour guide). I hope to finish in time to make a trip to quartzite, but I will have to see how that goes. You going this year? Don
Your new rig really looked perfect in the photos. I there a chance it went through any kind of flood? Does not sound like a California vehicle. History?
Photo of the damage possible?
If you can wait, I've got a Miller 200 wire feed here.
Pierce
Title: Re: Another Bulkhead Separation Story Part II
Post by: Don & Tys on December 04, 2011, 04:37:09 pm
I am with you on that goal! I don't wish to replace every part of this coach one piece at a time! I just want it to be structurally sound and to stop the rust form doing more damage. Once I get a more complete look, I will have to decide how to proceed. In the mean time, I am researching the rust converter options. Seems like it is somewhat controversial just how effective they are. Anyone with personal experience or just informed opinion on the subject, feel free to chime in!
Most designs are so overbuilt that they work exactly the same with half the structure removed. The goal here is probably not to build a new Foretravel.....
Title: Re: Another Bulkhead Separation Story Part II
Post by: Don & Tys on December 04, 2011, 04:42:11 pm
I would love to see this! I would also love to know if there are more substantial framing members under the floor. Anybody know? Don
It would be great to find some engineering drawings of the Travelride chassis...
A couple of photos after replacing all the tubular framing in that section.
Title: Re: Another Bulkhead Separation Story Part II
Post by: travelite on December 04, 2011, 06:57:11 pm
If the primary cause of the rust is overflow while filling the fresh water tank, assuming the overflow isn't thoroughly directed outside the coach, then maybe folks should consider some sort of automatic freshwater fill shutoff. Wanderlodge has been using a system like this for many years, and I suspect Prevost and Newell too. It's basically an electrically operated sporlan valve that takes an input form the tank level sensor. When the tank level reaches full the sporlan valve is automatically turned off interrupting shore water supply. Because of this system, I have never experienced an over flow from my fresh water tank while filling the fresh water.
David Brady '02 Blue Bird, Wanderlodge LXi NC
Title: Re: Another Bulkhead Separation Story Part II
Post by: JohnFitz on December 04, 2011, 06:59:13 pm
When I worked at Country Coach in the chassis group I remember seeing a FEA analysis report on one of their designs. The maximum stress point was right where the bulkhead joint is on a Foretravel in front of the rear axle. Worst case condition is a fully loaded basement under full braking force. Eventhough the CC was less of a monocoque design (4 slides with two large longitude beams) than a Unihome/Unicoach it still had the maximum stress in the same place. Here's my thoughts on it: think of the whole coach as being a beam. When it flexes down due to a load being applied the maximum stress occurs at the very top (roof in compression) and very bottom (belly floor in tension). You can think of stress as being like water - it doesn't like changing directions. Changing directions is exactly what it has to do when it encounters the wheel wells and has to travel around them. The stress at the very top (the roof) doesn't have any obstacles to go around. Like I said - just my own way of think about it and I can't help but think this is true of other manufacturers as well. If one wanted to take some of the stress out of the bulkhead area joint you could run a couple of tension rods between the front and rear suspension frames. Probably right where the lower parallel arms attach to the large "L" beam and run the rods on the exterior next to the fiberglass belly skin. I don't think I would ever do it because I just don't think it's necessary but I thought the idea might help illustrate the stresses. Of coarse there is also "rust jacking" going on if water is getting in that joint routinely in addition to the loads wanting to separate that joint.
Title: Re: Another Bulkhead Separation Story Part II
Post by: travelite on December 04, 2011, 07:19:05 pm
John, Thanks for the very informative description. Here's a view of the underside of my Wanderlodge. This is an example of the longitudinal beams that you describe.
Title: Re: Another Bulkhead Separation Story Part II
Post by: amos.harrison on December 04, 2011, 08:02:35 pm
A few years ago I was at FT having service work done when they replaced the floor on a coach. It seems the owner failed to notice a cracked coach battery. Electrolyte flowed freely until the batteries dropped to the pavement. I was shocked when I saw that bottom framework removed the same day the work started. I didn't see the coach finished, but it could have been the next day!
Title: Re: Another Bulkhead Separation Story Part II, removing fresh H2O tank... help!
Post by: Don & Tys on December 12, 2011, 09:30:35 pm
Well I thought I was about ten minutes away from sliding the freshwater tank out the passenger side of our 99' U270... three hours later, no joy and I had to give up because of darkness, threat of rain, and general discouragement:( I took off the trim that holds the compartment door latch, strut support (drilled out the rivets), and the weatherstripping. That trim is screwed into a piece of angle iron about. 1/8" thick and both the trim piece for the right side of the utility bay door and the forward vertical part of the passenger side wheel well covering (fender) is anchored to it. Problem is, the fresh water tank will not make it past the lip of the angle iron, yet I can't seem to see how the angle iron is held in place. It seems that it may just be held by caulking yet, somehow it seems too firmly anchored to be just caulking adhesion. The FW tank itself has bulging sides and it may be just applying some pig grease (or a liberal dose of WD40) and the application of enough force from behind (water heater side) might do the trick, but it is so tight! I don't want to damage the tank, but it has to come out! Help!!! Anybody who has done this or knows something about it, I am all EARS! ???