exterior shell question

[63tlf8]

If you end up using metal on the outside check out 3M's VHB (very high bond) tape.

I purchased a roll of low temp VHB tape but ended up not using it for the cladding. Used Polyeurethane instead. The tape is great stuff but it is not a one man operation with any larger size sheets. Grabs instantly!!! I will have used up the roll on other jobs so no major waste but it is very well worth a practice job to see if you can control the outcome. As mentioned removing it is horrendous. It came down to using the tape because I had it and accept a number of joints in the cladding or go for a one piece skin and use PE, which by the way is as good as VHB tape.

Tony

 

[tom]

Thanks for the input, Tony. I ended up not using it in case repairs had to be made but I still visualize laying on full sheets of skin with no seams. Ah,,, dream on!
Have a good day!

Tom

 

[jeepdreamer]

Panel adheasive...?

The semi-famous JSchreb that builds his own hart top on here has referenced sonething a couple time that I don't know much about. He calls it panel adheasive? and it is an auto body application "glue" for lack of a better term. He says that in some cases it is stronger than welding!?! Anyone know anything about this stuff? Name, application/uses, costs???

 

[nick disjunkt]

The semi-famous JSchreb that builds his own hart top on here has referenced sonething a couple time that I don't know much about. He calls it panel adheasive? and it is an auto body application "glue" for lack of a better term. He says that in some cases it is stronger than welding!?! Anyone know anything about this stuff? Name, application/uses, costs???

Sikaflex 252 is certainly a good panel adhesive. Stronger than welding? I'm not sure... It distributes the connection over a larger area so stresses don't get concentrated as on welds, for this reason it may be better than welding for joining panels to a forwork.

 

[arktrekker]

sikaflexs scares me. You only break that stuff out if you don't ever want to remove something. It brings the stick

 

[63tlf8]

sikaflexs scares me. You only break that stuff out if you don't ever want to remove something. It brings the stick

You don't need to use any two part system or ultra high performance products like Sikaflex. There are a large number of one part Polyeurethane adhesive / sealants specifically made for auto and or marine panel work that are ideal for the job. You aren't building a tank or a space shuttle, but if applied with even a small amount of diligence I cannot imagine a adhesive failure over the life of the camper.

Clearly almost any adhesive is unlikely to achieve the homogeneous outcome of welding when the contact area is measured in square millimetres, but applied just over the face contact area of the frame alone it will perform in the same order as auto spot welding. Add the massive contact area when you bond the cladding to the insulating foam (I used a different adhesive here) and it certainly exceeds the most stringent requirements.

If you really feel there is a viable and likely need down the track to remove the cladding then I would consider rivets. I believe I can remove mine with a long razor sharp blade (boning knife or such) but it would probably be better to scrap the cladding at that stage and replace with new. Mechanically cleaning the face and the risk of kinks in the sheet just wouldn't be worth the time and as an aside it is by far the cheapest cladding solution I have come across.

Tony

 

[dzzz]

A place that repairs trailers can skin the shell with aluminum in a day or two. Personally I would put coated metal on a metal frame and use standard materials and methods.
Using plywood for anything but an boat fiberglass finish looks, well, hillbilly. And I don't mean the good kind of hillbilly.

 

[jeepdreamer]

Speaking of semis...

So while researching stuff for insulating my home when I get around to build it...I came across this little idea that may or may not be me not having a clue..?
There is a picture on this companies web site that shows the application of a 2 part spray in expanding foam. Nothing new or novel there but as Ihave been looking into this stuff for home use I saw they have a "transpotation" application for this stuff. there is even a pic of it being used in a semi trailer as insulation (I'll try and add the pic). But if I read this correctly..the foam, once applied and cured, adds to the structual aspects in a large way? Am I wrong, maybe missed something important?
I'f I'm correct, then why could one not build a frame out of aliminim tubing, sheathe it in aluminum or painted steel via pop rivets, and then apply this foam to the inside...? Anyone...??

 

[gahi]

I wouldn't use pop-rivets, I think they would fail from vibrations and expansion/contraction of the skin from heat cycles. Enclosed trailers like car haulers use screws, usually with the security style heads. with the expanding foam, it sounds like it would work well. especially on a corrugated surface. On my teardrop, I did a 1" steel frame covered with .063 aluminum. Attached with screws. When installing the screws, I had to 1st drill a pilot hole. the screws strip before the steel frame so thats nice. If I ever need to repair damage I can remove the panel easily.

 

[jeepdreamer]

logical...sort of?

Gary,
What you said sounds logical about the rivets/screws. My only thought is that once the foam is sprayed in, expands, and fully cures...the only way that panel is coming off is to destroy it! That stuff is worse than glue!!:Wow1:

 

[gahi]

true, I was just going one subject at a time. If that were the case, I wouldnt use any exterior fasteners, just the VHB to hold it on. One other thing to think of, if your using aluminum, put the skin on outside in direct sun on a hot day. This expands it so that after its attached it wont bulge out on hot days. I did mine when it was about 85 out. And it still does it a little when it gets above 95 in direct sun.