Hi all,
My dads U320 lost a right rear airbag during travel and destroyed the upper well area. After reading some old post we have decided to cover the damaged area with the 3M 5200 product and install a piece of stainless to further protect the sealant and exposed area. Dad is insistent to use screws going thru the stainless to better hold in place. May not be necessary but that his choice. What I discovered is the screws up to 2" do not grab any material to hold. Has anyone used screws any longer in length, maybe going into the wood that we saw when it was exposed? Thanks Mike
Longer screws might open up a can of worms. Maybe us a stud finder to be able to use short screws. If the area was cleaned up the 5200 is about as strong as you are going to ever need.
You might try using some large head 3/16 aluminum rivets, about 1/4" long
Thank You both for the reply's. That is what I'm afraid of putting longer screws into wires, pipes etc and not knowing until it's too late. I will have a talk with Dad about eliminating the stainless and just using the 5200 as a cover. The tire rubbed completely thru the wheel well area and exposed a black pipe ( looks water or sewer related ) that sits just above the cut in the wood flooring. I filled in the hole in the floor and now I have only the indentions were the tires rubbed to fill-in to make flat. Thank Mike
You can still use the stainless with one of the good adhesives.
I will take the advice given and go the other route. Stainless only no screws.
Next Question: I applied a layer of 5200 already to the wheel well area and it's almost dry. This 5200 is the multi day drying type. Can I reapply another layer of 5200 and adhere the stainless piece without any issues to the dried portion? Thanks Mike
I can't find any information that would prevent you using another layer and putting the stainless on. Use something like jacks and wood to press it up tight until it drys.
Yes Sir will do. I just call 3M and talked to the adhesive division. I went thru what I already applied and gave them your idea and they said the stainless will adhere without issue. They did recommend using a scotch brite pad to give the surface slight rough surface. I can't express enough how much I appreciate all the ideas and advice. I will post some finished photos but it will be. a few days until it dries. Thank You Mike
I just finished mine. I used Henry's roof mastic to fill the hole and then had a local plastic company cut 1/4 inch x 2x2 foot pieces of abs. I then drilled 8 holes in the abs perimeter, purchased large head 1 inch screws, bought the extra hold liquid nails in tubes, sanded the adhesive side of abs, liberally smeared the adhesive on, screwed in place and blocked the abs while drying in the middle using a gallon paint can on top of the tire over night. Just make sure the coach isn't going to fall with the paint can under it. When dried I went back and sealed all the abs edges with the same adhesive and seems fine. I did have enough factory abs undamaged with a 2x2 piece to be able to screw into and hold it in place. If it happens again, I'll probably go to 1/8th abs because it is so much lighter that 1/4 inch but not as tough of course.
Anyone see a tire cut risk if tires contact metal above tire? Now there is no metal around tires.
That's why I used plastic. I think metal is concerning
That's why I used plastic. I think metal is concerning but i/4 inch plastic jammed could probably cut a tire as well
Thin sheet stainless bonded with 5200 would just wear through if the tire rubbed in my opinion.
Wear though with a sharp edge?
Without it actually happening it is pure conjecture whether the beveled edge would remain bonded to the 5200 or become loose and create a sharp edge hanging down. As I posted my opinion ymmv.
Update on repair:
Want to confirm that the 5200 will bond to a cured application of 5200. We lightly scored the first layer as recommended by 3M and then applied a complete heavy covering of the 5200 to top side of the stainless. I'm sure I used more than needed as some squeezed out of the edges when we braced it. I simply used a putty knife to smooth the excess out. We braced the the four corners and added three additional supports in the area with 2x4's wedged tightly against the stainless. We let that cure for 4 days and when we removed the braces all was tight. Just for safety I applied a bead around the outer edge of the sheet to give complete coverage. We road tested the coach for about 150 miles luckily in the rain and we see no signs of issues. Mike
Note: Wear gloves and clothes that are disposable. It will not come wash off jeans/shirts and it's very difficult to get off skin!