bulkhead blues

Topic: bulkhead blues (Read 12047 times) previous topic - next topic

Re: bulkhead blues

Reply #225 – July 21, 2012, 04:34:57 pm

On my u295 most of the bulkhead rust is in the very bottom area of the joint , and then only the sheet metal that rolled under the fiberglass bottom. Most of the sheet metal that rolled under is completely gone. Gam

Re: bulkhead blues

Reply #226 – July 22, 2012, 12:18:49 pm

Quote from: wolfe10 – July 20, 2012, 10:20:19 pm

Have
Have you found the upper side of the L bracket unsealed??? Mine was factory sealed-- just crawled under to confirm.

Brett

Can't speak to the front bulkhead as I had catastrophic failure there, which I am still addressing. However I did check the rear bulkhead and after removing the accumulated dirt and rocks I scraped the "seam" with a small putty knife. There are some spot welds along that seam. However there is no sign of any sealant having been applied to that area. That will not be the case when I finish addressing this bulkhead issue, welds or no welds. Sure wish I had joined the forum before I purchased, would be in "recreation" mode instead of "major puttering" mode.

Roland

Re: bulkhead blues

Reply #227 – July 22, 2012, 11:25:53 pm

Quote from: wolfe10 – July 20, 2012, 10:20:19 pm

Have
Have you found the upper side of the L bracket unsealed??? Mine was factory sealed-- just crawled under to confirm.

Brett

Brett,
I have written this three times and keep losing my drafts. It may be something associated with my attached YouTube file which passes on my unexciting confirmation of no seal (angle iron to vertical sheet metal).

I have proven to myself, at least, that both my after and forward bulkhead joints are not sealed at the angle iron (top surface) to vertical sheet metal joint. Thus, I believe that, for '98 at least, all FT's are not sealed at that joint.
After I repaired my failed fasteners, I chose to not seal up these areas with undercoating. When I was in college, I worked in a decent auto body shop and I saw a lot of undercoating horror stories. Applied to improperly prepared surfaces, sprayed-on undercoating can easily do more harm than good by not adhering well which leads to the trapping of moisture and chlorides in undesirable places.

That, and because I don't operate the coach in salt environments any longer, led me to keep the repaired joints open for ease of observation. I just treat them with Corrosion-X to render them corrosion neutral. I believe that Corrosion-X will seep all the way from top to bottom, through my angle iron (top surface) to vertical sheet metal joint.

Anyway, my vertical sheet metal is very thin, (maybe 1/16") and infrequently tack welded, so I'm curious as to how yours is sealed (and which model year FT stopped sealing that interface).

Note: removed YouTube link. Not working properly!

FWIW,
Neal

Re: bulkhead blues

Reply #228 – July 23, 2012, 10:19:17 am

Quote from: Neal Pillsbury – July 22, 2012, 11:25:53 pm

I just treat them with Corrosion-X to render them corrosion neutral. I believe that Corrosion-X will seep all the way from top to bottom, through my angle iron (top surface) to vertical sheet metal joint.

FWIW,
Neal

I have been debating Corrosion-X verses undercoating for my bulkheads. Living in a salt area I want the best rust protection possible. My other vehicles I rinse the undercarridge's off several times a winter. Of course the coach will only be exposed on it's way out of Maine. (We don't return untill spring).
As Neal said I have also seen that water can get behind improperly applied undercoatings and wreak havoc. So I wonder what protection you would get from sealing the top and bottom of the angles and simply cleaning and applying Corrosion-X on an annual or semi-annual basis verses undercoating?

Dean

Re: bulkhead blues

Reply #229 – July 23, 2012, 12:07:55 pm

I agree with Neal and Deans point on the "badly applied underseal" possibly causing later problems, but would add that if you do not clean and properly address this issue BEFORE coating then that is asking for more trouble!! I would hope that anyone doing this job would have taken that for granted, sort of not washing your hands before eating after going "you know where"
I had great success with spraying a wax-oil mixture into all the panels ( and underbody) of my 735 BMW (drilled holes then plastic plugs) and not seeing any rust in 20yrs. The thing looked like new when I sold it. I have done the same thing with the FT. I would think if you did spray Corrosion X first then leave for a few days to soak in you could then coat. Double protection??
John H

Re: bulkhead blues

Reply #230 – July 23, 2012, 12:43:43 pm

Quote from: John Haygarth – July 23, 2012, 12:07:55 pm

... sort of not washing your hands before eating after going "you know where"

This reminded me of the difference between a doctor and a mechanic. The doctor only washes his hands *after* going "you know where".

Craig

Re: bulkhead blues

Reply #231 – July 23, 2012, 12:54:08 pm

Quote from: John Haygarth – July 23, 2012, 12:07:55 pm

I would think if you did spray Corrosion X first then leave for a few days to soak in you could then coat. Double protection??
John H

Well I thought about that but not sure how corrosion-x and undercoating would adhere to each other. Yes, prep is vital when undercoating anything.
There is a guy not far from me that makes a pretty good living undercoating cars and trucks with a sprayed on paraffin wax. May be something to consider.

Dean

Re: bulkhead blues

Reply #232 – July 23, 2012, 01:05:03 pm

Does anyone know how to remove one end of the steering control arm without damaging the ball joint or the rubber seal. I do not want to replace the ball joint and/or disturb the alignment. I have to drill 16ea 3/8" holes for my bolts and want to use a magnetic base drill and a jig so that all the holes line up and are centered on the box beam. If I can release one end of the steering control arm I can swing it out of the way and will have room for the mag drill. Suggestions anyone?

Roland

Re: bulkhead blues

Reply #233 – July 23, 2012, 01:54:24 pm

I guess we will never arrive at an end all be all consensus as to what should be done to avoid or fix bulkhead problems. this week I had the opportunity to have my bolts torqued. since my bulkheads looked to be in good shape, with no separation, I was surprised to find I had one broken bolt on the forward bulkhead outside passenger side and three broken on the aft bulkhead, two outside drivers side and one outside on the passenger side.

most of the broken bolts I have seen on other coaches also seem to come from the outer locations of the bulkhead. I am in no way qualified to give definitive answers or to arrive at definitive conclusions, but most of the broken bolts I have seen, seem to have suffered from the same stresses that caused them to fail. I also believe that this stress is caused by extreme twisting stresses that are put on the coach from time to time. In addition to this, I believe that the horizontal strength of the bulkheads could have been more evenly distributed had there been more fasteners installed nearer the outer reaches of the bulkheads.

at this time I have no plans to remove the broken bolts, I am however going to avoid through bolting in favor of installing two more roloks of the same size, one on each side of the broken bolts. I will keep the area clean, will apply corrosion x and inspect the area regularly.

I am not in any way offering advice here, this is just my opinion formed from everything I have read here and elsewhere. this is just what I see as a satisfactory and easy fix for my coach.

Re: bulkhead blues

Reply #234 – July 24, 2012, 11:14:40 pm

Wayne,

I tend to agree with your reasoning regarding bolt failure but am definitely in the minority. I think your repair method is preferable to bolting as I am told the thin tubing isn't rigid enough to torque a grade 8 thru bolt to spec. Roloks, due to their nature and the material they are seated in can be driven to spec.

I fully intend to increase fastener density in bulkheads using Roloks. Will replace all 17 year old Roloks and will look at upsizing them as the next size up can be driven in existing pilots. As far as corrosion protection, will use LPS3 which is a liquified wax with excellent staying power-years. One thing to realize about using this stuff or CorrosionX on the faces of the bulkhead angle is that it will work against you strength wise as it's a lubricant and will decrease friction between parts-which is some of what you are trying to achieve with fasteners of course. A good alternative might be a conversion coating like Conquest which is quite viscuous and will wick into the joint. It requires at least a light surface coating of rust to work and will tend to lock parts together and form a hard black durable coating. Like your coach mine is rust free.

Re: bulkhead blues

Reply #235 – July 25, 2012, 03:09:44 pm

Quote from: Chuck Pearson – July 20, 2012, 12:38:19 am

If he loans his torque wrench make a mental note to self. "Find someone else to be my A&P mechanic."

As a former A&P..... X2 I used to spend a bunch of $$$ keeping mine calibrated! Re-calibrated them on a time schedule and if they were ever dropped. As a certified repair station, the FAA required this! Better bet would to bring a 12 pack of beer to the Mechanic and ask him to stop bye with the wrenches!

OK. I have just gone through this entire thread, & checked my bolts. When I bought the coach, I did a visual inspection of both bulkheads and the joint along with the rest of the underbelly steel showed some rusting, but there was no joint separation, could not even get a playing card into it. This morning, I took my trusty Snap-on torque wrench and found some broken roloks, 3 at the front bulkhead and 6 at the rear. two spots are spread wide enough to get a playing card in...... just did not see that at the previous inspection.

Choices are 1: Thru-bolt with big washers only broken bolts 2: Replace all rolocks with bolts 3:sister new rolocks next to each broken one 4: remove broken rolocks and replace with the next size larger..... Seems like just replacing the broken ones with bolts would be the easiest at this point.

HELP to many choices

Steve

I am still confused as to which choice I must do...... only want to do it once

Re: bulkhead blues

Reply #236 – July 25, 2012, 05:29:01 pm

Steve,

I also found others that were rusted solid and broke with a bang when I tried to remove them. It was a fresh break, not from rust jacking. I called several large bolt sources to get opinions. I was told that there was no advantage to ordering Rolocs as they were normally ordered by manufacturers as they were easy and quick to install. A fresh hole could be drilled and tapped and a tap bolt (full thread) installed. Most everyone suggested 316 stainless tap bolts as the best solution. They cost a lot more than 18-8 stainless but I found a supplier with 3/8" 316 tap bolts for under $2 each. Fastenal wanted $6.70 each. I ordered 50 and will double the amount that is presently installed. They are a lot stronger than 18-8 and the most corrosion resistant of anything available. Will install 316 flat washers. Since stainless can gall, anti seize will be used with torque reduced 20% Here is a good article on stainless bolts and includes a section on using stainless with mild steel in wet, salty conditions. http://www.ssina.com/download_a_file/fasteners.pdf

I don't see any way of removing the bolts that have broken off. Loosening before checking torque or to inspect risks breaking some off requiring sistering right away to maintain structure 100%.

As each one breaks, I can feel the angle iron is under quite a bit of static stress. The feeling and vibration the whole rig makes is an indication that the coach does not have to be underway for a load to be on the bolts.

Grade 8 bolts would have to be installed with a backing plate at the other end. The last 2 feet from the end bolts go through the .125 wall thickness square tube and into another square tube of only .060 wall thickness. Torquing a grade 8 to specs might be risky even with a backing plate on top of this 16 gauge tube. Corrosion resistance with a plated steel bolt is only as good as the thin coating. That can be compromised by threading it into the tubing, friction under the head when tightening or even from the socket that installed them.

After all this I am still convinced the problem is 100% with rust and rust jacking and has nothing to do with chassis flexing IF the original bolts and tubing have not been damaged from a wet environment, either from road spray for a leak from above. It's just tough protecting the total length of all the bolts down in this location.

I just replaced all the torx drive cap screws where the entry steps fold up (the ones visible when the stair is down). The heads were a little rusty so installed stainless allen button head caps in their place. I had to buy a top quality T25 drive (China T25 twisted) to get all the old ones out as they had also rusted severely and took a lot of effort to remove them. My rig is very clean in almost all areas underneath so this has all been a big surprise.

Pierce

Re: bulkhead blues

Reply #237 – July 25, 2012, 05:57:01 pm

Cool Beans!

OK... now there is one more choice........I do like this idea better than self tapping bolts. How long of a tap would we need? I have never seen any that are very long. And, what company did you find them for that price? OH yeah, how long?

Steve

Re: bulkhead blues

Reply #238 – July 25, 2012, 06:36:30 pm

Hi Pierce,
Did you look into thread forming taps? These use pressure to for threads. I believe it is similar to the thread rolling process that the Roloks use and makes stronger threads than typical taps. I got one at McMaster-Carr, but they aren't long enough to thread both faces of the tube at the same time, which I believe would be essiental for what you propose... Conventinal taps in the required length (for at least the first 1.5" tube) seem to be readily available. It might be worth using Roloks for the purpose of making the theads, would have to expieriment on some scrap of course...
Don

Quote from: Pierce & Gaylie Stewart – July 25, 2012, 05:29:01 pm

I called several large bolt sources to get opinions. I was told that there was no advantage to ordering Rolocs as they were normally ordered by manufacturers as they were easy and quick to install. A fresh hole could be drilled and tapped and a tap bolt (full thread) installed. Most everyone suggested 316 stainless tap bolts as the best solution. They cost a lot more than 18-8 stainless but I found a supplier with 3/8" 316 tap bolts for under $2 each. Fastenal wanted $6.70 each. I ordered 50 and will double the amount that is presently installed. They are a lot stronger than 18-8 and the most corrosion resistant of anything available. Will install 316 flat washers.

Re: bulkhead blues

Reply #239 – July 25, 2012, 07:11:13 pm

The existing bolts are 3 inches. Here is the site: 3/8"-16 - Tanner Bolt & Nut Corp.

I ordered a box of 3/8-16 X 3" in 316 stainless. I also ordered two boxes of washers. 5/16" washers usually are a good fit for 3/8" bolts but in this case, I ordered both sizes so I would be able to choose and not wait.

Taps: Taps are available in lots and lots of lengths and styles. Here is a page with descriptions for each typehttp://www.newmantools.com/taps/styles.htm The long types are toward the bottom. If you did not want to wait for an order, you could call Grainger. They have a store in lots of towns.

And if this was not enough, Tanner's fastener page has self tapping bolts, in grade 5 with special corrosion protection. This is what should have been used originally. Fasteners - Ultracon Screws, Screws, Nuts, Bolts, Washers, Buy Online, Everyday

They are only 2 1/2 inch but may reach. Will have to use a rod with a small hook on the end to see exactly how far is needed.

Here are the specs on the self tappers:

• Eliminates thread-tapping operations
• E-Form® configuration overcomes friction build-up and reduces drive torque
• Roll forms own work-hardened thread to resist loosening cause by vibration or thermal changes
• Provides enhanced pull-out performance
• Well-suited for metal applications such as steel and aluminum
• Flex Technology heat treat provides required strength and ductility
• Virtually immune to delayed embrittlement failures
• Stalgard GB coating provides 1000 hours of salt spray resistance (per ASTM B117)
• Accept standard nuts and washers if required

Specifications

• Diameters: 3/8", 1/2", and 5/8"
• Lengths: 1-1/2", 2", and 2-1/2"
• Head Style: Hex washer
• Threads: E-Form five-lobe thread forming
• Material: Alloy steel
• Finish: Silver Stalgard® GB coating
• Grade 5: meets ASTM A449 specifications (120 ksi strength)

When I started this whole thing, I thought the tubing on the other side of the bulkhead would be have the same wall thickness as the angle iron and make this an easy operation. Another surprise.

Don,

The grade 5 self tapping screws above may roll the threads to be what you are speaking of. And speaking of that, would a 2 1/2" self tapper reach? Looking at the original Roloc, I don't see any kind of corrosion protection that has been applied.

Pierce

Re: bulkhead blues

Reply #240 – July 25, 2012, 07:23:42 pm

Good info Pierce! If I remember right, I was considering these as well but I was concerned about the length. If you are overcoming any gap at all under tension, I figured they would be a smidge short... that was about the time I discovered that I would need to remove the guts of the wet bay anyway, so I didn't pursue it. 2" of load bearing length minus any gap, 1/4" angle, washer thickness (say an eighth), 1/16" sheet metal, 1.5" squarte tube = 1 &15/16" plus gap, unless I am adding wrong. Add to that the possibility of being a bit off perpendicular... too close to call IMO... If only these came in 3", it would be perfect!

Quote from: Pierce & Gaylie Stewart – July 25, 2012, 07:11:13 pm

Don,

The grade 5 self tapping screws above may roll the threads to be what you are speaking of. And speaking of that, would a 2 1/2" self tapper reach? Looking at the original Roloc, I don't see any kind of corrosion protection that has been applied.

Pierce

Re: bulkhead blues

Reply #241 – July 25, 2012, 07:34:27 pm

Quote from: acousticart – July 25, 2012, 07:23:42 pm

Good info Pierce! If I remember right, I was considering these as well but I was concerned about the length. If you are overcoming any gap at all under tension, I figured they would be a smidge short... that was about the time I discovered that I would need to remove the guts of the wet bay anyway, so I didn't pursue it. 2" of load bearing length minus any gap, 1/4" angle, washer thickness (say an eighth), 1/16" sheet metal, 1.5" squarte tube = 1 &15/16" plus gap, unless I am adding wrong. Add to that the possibility of being a bit off perpendicular... too close to call IMO... If only these came in 3", it would be perfect! OTOH, they might just be the thing to use as a tap without a washer and if there is no gap to speak of...

Re: bulkhead blues

Reply #242 – July 25, 2012, 07:50:36 pm

Pearce,
Thanks for sharing your research.....

Re: bulkhead blues

Reply #243 – July 25, 2012, 07:52:50 pm

Quote from: Pierce & Gaylie Stewart – July 25, 2012, 07:11:13 pm

The existing bolts are 3 inches. Here is the site: 3/8"-16 - Tanner Bolt & Nut Corp.

And if this was not enough, Tanner's fastener page has self tapping bolts, in grade 5 with special corrosion protection. This is what should have been used originally. Fasteners - Ultracon Screws, Screws, Nuts, Bolts, Washers, Buy Online, Everyday

They are only 2 1/2 inch but may reach. Will have to use a rod with a small hook on the end to see exactly how far is needed.

Here are the specs on the self tappers:

• Eliminates thread-tapping operations
• E-Form® configuration overcomes friction build-up and reduces drive torque
• Roll forms own work-hardened thread to resist loosening cause by vibration or thermal changes
• Provides enhanced pull-out performance
• Well-suited for metal applications such as steel and aluminum
• Flex Technology heat treat provides required strength and ductility
• Virtually immune to delayed embrittlement failures
• Stalgard GB coating provides 1000 hours of salt spray resistance (per ASTM B117)
• Accept standard nuts and washers if required

Specifications

• Diameters: 3/8", 1/2", and 5/8"
• Lengths: 1-1/2", 2", and 2-1/2"
• Head Style: Hex washer
• Threads: E-Form five-lobe thread forming
• Material: Alloy steel
• Finish: Silver Stalgard® GB coating
• Grade 5: meets ASTM A449 specifications (120 ksi strength)

Sometimes procrastination pays off. I was putting off drilling holes for the 3/8" bolts. I'm liking the idea of these self tappers. The length 2 1/2" is long enough ifor my front bulkhead and adding nuts on the back side may be a bonus. As I have already cut into the filon and cleared the area out on my front bulkhead I wiil add nuts and washers as well. May be the best of all worlds.

Roland

Re: bulkhead blues

Reply #244 – July 25, 2012, 08:12:25 pm

Roland,

If your going to add nuts, check the photo at the Tanner site. Looks like you have to subtract around a quarter inch on the overall length so the nuts will have enough thread to grab onto.

Don,

Glad you came up with the numbers. I had figured the self tappers were long enough but was also a little hesitant. We have a 1500 mile trip to S.Cal in less than a week in the U300 and want to get things secure just in case.

If anyone has a bulkhead separation issue, it would be easy to make a tool that goes over the horizontal angle iron with an adjustable stop down where the bolts are on the vertical face. It would extend down under the coach several inches . The same tool could be placed on the angle iron at the front end of the coach and then a come-a-long could easily pull the two towards each other so bolts could be installed without having to bridge any gap. Will draw up an illustration of such a tool if anyone is interested.

Pierce

Re: bulkhead blues

Reply #245 – July 25, 2012, 08:32:03 pm

I was actually desperate enough to consider using a couple of garage door tensioners installed on the coach if we decided to try for Texas...LOL. A sturdy comealong should be able close the gap particularly if you add a bit of leverage to the mix as you say (perhaps like a sturdy piece of retangular tubing inserted between the trailing arm shackles). Pierce, if you make it as far south as San Diego maybe we meet up in person...
Don

Quote from: Pierce & Gaylie Stewart – July 25, 2012, 08:12:25 pm

Roland,

If your going to add nuts, check the photo at the Tanner site. Looks like you have to subtract around a quarter inch on the overall length so the nuts will have enough thread to grab onto.

Don,

Glad you came up with the numbers. I had figured the self tappers were long enough but was also a little hesitant. We have a 1500 mile trip to S.Cal in less than a week in the U300 and want to get things secure just in case.

If anyone has a bulkhead separation issue, it would be easy to make a tool that goes over the horizontal angle iron with an adjustable stop down where the bolts are on the vertical face. It would extend down under the coach several inches . The same tool could be placed on the angle iron at the front end of the coach and then a come-a-long could easily pull the two towards each other so bolts could be installed without having to bridge any gap. Will draw up an illustration of such a tool if anyone is interested.

Pierce

Re: bulkhead blues

Reply #246 – July 25, 2012, 09:21:41 pm

Don,

This one is to Santa Barbara. In October, we are headed to Kent, OH, S. Carolina and across the U.S. via the southerly route. Will hit Puerto Panasco for a little while and would love to stop by unless you are our way earlier. Pulling a horse trailer with household stuff for the kids so will be w/o toad.

Possible Mulege or PV late in the year. Would love Company.

Pierce

Re: bulkhead blues

Reply #247 – July 26, 2012, 07:18:51 am

Thinking back over a suggestion Pierce made regarding sloshing the inside of the square tubing with linseed oil a la Taylorcraft, might it be possible to seal the tube enough to just fill it with oil? That'd take care of the need for anything other than a standard 3" Rolok. Even if it wasn't possible to permanently fill it, a one time soaking with LPS3 would permanently coat both new and old bolts with greasy wax.

A couple of considerations though. The vast majority of original fasteners do not fail. The ones toward the outside of the bulkhead seem to be the culprit for whatever reason. Adding fasteners in this area, whether corrosion resistant or not would most likely solve the problem for many years to come.

Re: bulkhead blues

Reply #248 – July 26, 2012, 02:37:38 pm

Got up my courage this morning and crawled under the rear bulkhead to clean, wire brush and undercoat it. I had to remove the sewer hose tube to be able to access the top of the angle. I noticed that there were 4 evenly spaced plastic plugs under the beam and 4 different type of bolts above each. Also noticed a waxy substance squished out around several of the bolt heads.

I am guessing that someone had FOT or another shop drill the access holes and add the 4 evenly spaced bolts. I am hoping the waxy stuff is the result of the beam being sprayed or treated at that time. There was no rust in the bottom seam or on top of the angle and everything looked really good. I vacuumed all the gravel etc. off the top of the angle then wire brushed everything with a drill and rotary brush then scrubbed it all down with paint thinner.
Masked off the bolts and just beyond the plastic plugs then blew a can of undercoat on it. It was quite a job but I am confident that it's well protected and was worth doing. I intend to do the same to the front bulkhead.
The only thing I would add is make sure you wear throw away clothes. That undercoat get's on everything.
Dean

Re: bulkhead blues

Reply #249 – July 26, 2012, 11:45:27 pm

Dean,
My 2003 has the same four plastic covers with nutted bolts front and rear. It looks to me like it was part of the original build because those four bolts are spaced evenly along with the Roloks; in other words they're not sistered beside another bolt. Also, the four nutted bolts are evenly distributed across the beam, same front and rear. As with yours, several of my bolt heads also show what looks like a caulk or sealant under the head.
If you remove those plastic covers, you can get a look inside at the nut and the condition of the inside of the tube. They simply snap back in.

Mike
2003 u295, #6063

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