Another Bulkhead Separation Story Part II

Topic: Another Bulkhead Separation Story Part II (Read 2279 times) previous topic - next topic

Another Bulkhead Separation Story Part II

December 02, 2011, 11:30:42 pm

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

Re: Another Bulkhead Separation Story Part II

Reply #1 – December 03, 2011, 12:43:24 am

Don,

Go to Barry "Beam's" website. Bulkhead Separation
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.

Re: Another Bulkhead Separation Story Part II

Reply #2 – December 03, 2011, 01:28:31 am

Thanks Don,

Every little bit of encouragement helps!

Don

Quote from: Don Hay – December 03, 2011, 12:43:24 am

Don,

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.

Re: Another Bulkhead Separation Story Part II

Reply #3 – 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!

Re: Another Bulkhead Separation Story Part II

Reply #4 – 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

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

Re: Another Bulkhead Separation Story Part II

Reply #5 – 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

Re: Another Bulkhead Separation Story Part II

Reply #6 – 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.

Re: Another Bulkhead Separation Story Part II

Reply #7 – December 03, 2011, 01:03:37 pm

Quote from: Donmystic1 – 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.

Re: Another Bulkhead Separation Story Part II

Reply #8 – December 03, 2011, 01:33:02 pm

Quote from: Donmystic1 – 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.

See my post above for a link to how to check. Then look at the photos/description in Pat's post.

Brett

Re: Another Bulkhead Separation Story Part II

Reply #9 – 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 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

Re: Another Bulkhead Separation Story Part II

Reply #10 – 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

Re: Another Bulkhead Separation Story Part II

Reply #11 – 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

Re: Another Bulkhead Separation Story Part II

Reply #12 – 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.

Re: Another Bulkhead Separation Story Part II

Reply #13 – December 03, 2011, 02:37:08 pm

Quote from: Benjie Zeller – 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

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.

Re: Another Bulkhead Separation Story Part II

Reply #14 – 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

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Re: Another Bulkhead Separation Story Part II

Reply #15 – 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 . 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

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Another Bulkhead Separation Story Part II

Reply #16 – December 03, 2011, 03:49:51 pm

Quote from: Benjie Zeller – December 03, 2011, 02:58:36 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

Re: Another Bulkhead Separation Story Part II

Reply #17 – 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.

Re: Another Bulkhead Separation Story Part II

Reply #18 – 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.

Re: Another Bulkhead Separation Story Part II

Reply #19 – 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

Quote from: wolfe10 – 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.

Re: Another Bulkhead Separation Story Part II

Reply #20 – 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

Pierce

Re: Another Bulkhead Separation Story Part II

Reply #21 – December 03, 2011, 07:27:02 pm

Quote from: Pierce & Gaylie Stewart – 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

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.

Re: Another Bulkhead Separation Story Part II

Reply #22 – 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.

Re: Another Bulkhead Separation Story Part II

Reply #23 – 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.

Re: Another Bulkhead Separation Story Part II

Reply #24 – 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.

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