We bought our 2004 U270 in September of 2021. It has been quite the learning experience. I have been cleaning inspecting and fixing on a regular basis and have done a lot. The bulkheads have been a concern of mine since before I bought it. I did a superficial visual inspection before we bought it. It seemed to look pretty good to my untrained eyes. The things I noticed 1) there are a couple areas on the front and back where the fiberglass belly skin was not glued to the square tubing the adhesive or caulk had failed and there was some visible rust when you looked between the fiberglass and square tubing. These areas were about 6 or 8 inches in length. 2) 4 thru bolts were added at some point to the front bulkhead and 4 thru bolts were added to the rear bulkhead. The thru bolts are evenly spaced one on each side and two in the middle. They have the plugs in the fiberglass as has been described in other bulkhead repair threads. All the rollocks passed the torq test none are broken or stripped out. I have been putting off looking at this because I was afraid of what I might find. But it has kept me awake worrying about it. So today decided had inspect further and go from there. I have started on the front. So the area that was unglued and loose I took a multi tool and cleaned out the area of old caulking or adhesive. I also used the blade on the multi tool to scrape the rust off the tubing. It is not down to clean metal but all loose rust is off. I decided to unstick the fiberglass all the way across to see the condition of the tubing, it looked better had a little rust but nothing flaking off. The fiberglass is still glued to the foam insulation and from the little I can see doesn't seem like it has been wet. Overall I think it looks pretty good. My thoughts are to clean with acetone reglue fiberglass to tubing. Clean angle iron mask off bolt heads and spray with automotive undercoating. My questions are should I treat the tubing with a rust converter or something else or just glue it back down without treating it. I bought 3M 4200 marine adhesive sealant to reattach would this be a appropriate adhesive? Or would something else work better? I know there is a wealth of knowledge in past post on this subject but was spending way to much time reading and not enough time doing. Will add pictures. We all like pictures. Tom
Here are a couple pictures still need to clean it up a little more.
We have moved away from 3M in the boating world to versions of Sikaflex.
Available at West Marine and other outlets
Sikaflex®-291 | Watertight Sealing & Bonding (http://usa.sika.com/en/industry/global-industry-content-pages-to-keep/commercial-vessels/elastic-sealing-bonding/watertight-sealingbonding/sikaflex-291.html)
I would use Sikaflex over 3M in this application.
Thanks I will check out the Sikaflex.
After removing as much rust as you can, take a picture and contact the manufacturer of the adhesive product you choose. 3M and Sikaflex have help numbers. They can tell you if you can treat the metal and if so with what.
Wouldn't hurt to contact a couple of them to get their recommendation on what product to use as well. Adhesion, with a little flexibility is critical. Suspect most products will give you the waterproofing you need.
As usual, Brett nails it. There are a number of Sikaflex formulations. Some with more flexibility than others.
Check out " Extend" rust treatment for the tubing .
https://www.lowes.com/pd/LOCTITE-Rust-Neutralizer-10-2-oz-Rust-Remover/4764091?cm_mmc=shp-_-c-_-prd-_-pnt-_-ggl-_-LIA_PNT_133_TS-Sanding-Sundries-Surface-Buckets-_-4764091-_-local-_-0-_-0&ds_rl=1286981&gclid=Cj0KCQiA_8OPBhDtARIsAKQu0gYTCoeCk9n-m13Lr4BMSq4ovfu4qZcab2C43--dcqaFW5uSc9I_Hn4aAvNUEALw_wcB&gclsrc=aw.ds
That's great advice seems simple but probably wouldn't think of it. Also here are more pictures from the front axle looking back. Hard to get good pictures but is there anything that looks abnormal or concerning. If so I can investigate further. Talking about the center area to me I don't see any thing alarming. I plan on doing the back the same as the front. I also am going to spend some time around the wet bay looking for any signs of problems, so far not seeing anything else. Also is there a way to sand the rust off that metal without opening it up more?
Thanks Mike will check that out.
I'm curious about the four through bolts that were added to Tom's front and rear bulkheads. My coach has these also exactly as Tom describes. I wonder if that's an indication that these were added by Foretravel sometime after the coach was purchased (maybe under warranty or a silent recall?) or if maybe they started adding these at the time of construction in response to the problems that others were having. I believe I'm the third owner of my coach but I have no service history for it.
Tim, Sika and 3M are both fine products. Is there something in particular that you feel would make the 3M unsuitable for this application? Everything I've read indicates that the 3M is virtually unremovable, although I might be confusing the 4200 and the 5200.
It is my understanding the 3m 5200 is unremovable. The 4200 somewhat removable god forbid I have to open back up but who really knows.
Everything is removable it's just a question of how much other stuff you're prepared to sacrifice to remove it ?
I believe the extra through bolts that you have noticed on yours were added by Foretravel on their production runs sometime after 2000, I think perhaps around 2002. I have previously posted on bulkhead joints once or twice... And I made a post with pictures from a few different years of Foretravel's of the rear bulkhead joints showing some differences. Here is a link to that post with pictures which may add some information for the curious.
Bulkhead Joints through the years... (http://www.foreforums.com/index.php?topic=16860.msg109888#msg109888)
Don
Don I just read your post from 10 years ago. It confirms that those 4 through bolts on the front and rear bulkheads were installed in production. I feel better about that. I thought that someone might have been trying to fix a precived problem. I now think it was a belt and suspenders thing, at the factory.
Tom, whichever adhesive you use you may want to have some means of uniform clamping ready. Perhaps a 2x4 under the fiberglass with some hydraulic or screw jacks pressing up against the weight of the coach. Cover the top of the 2x4 with clear packing tape which will keep it from permanently sticking.
Yes, and have the safety stands in place, air out of suspension. You don't want the coach to either settle or level during this process!
Loctite max works about the same as 5200. I use it on my airplane .
All great advice was going to clamp with a 2x4 didn't think of the packing tape. Will make sure I let the air down onto the safety stands. In a holding pattern now waiting on my Sikaflex 252 arrive.
You can use several 2x4 posts with opposing wedges under the 2x4 to provide uniform clamping pressure. Easy to do if you don't have other options.
I glued it together last night. I had everything together to clamp it. 3 jacks and a 2x4. I didn't end up clamping it as I had to pry the fiberglass away from the steel tubing to get the adhesive in there. The Sikaflex 252 is super sticky. After I got the glue in there I just pushed together. It seemed pretty stuck on there. I just went back every 20 minutes and checked on it by pushing on it, to make sure it was looking good. I left it overnight, this morning it is glued down perfectly.
Tom,
So, did Sikaflex recommend priming the box beams or leave them raw?
T and M
Did you happen to take pics of the finished fix?
I could never get any one to answer their tech line said to email which I did and never got a response. I did spray a self etching primer. I put undercoating over the area, as the last step.