Hi SCOTT JORDAN. The favourite method is to used finishing resin. It must not be the type used on Fibreglass but is in acutal fact an epoxy resin. I used to use it quite a lot on Model Aeroplanes. Not the 5 minute stuff. But one that you can work with and it will cure overnight.
Park the RV next to an adjacent wall.
Have a panel board large enough to cover the delamination area.
Have some 3x2 (or simlar) and wedges to able to wedge the board against the side of the RV and the wall.
Drill holes along the top of the delamination area and then alternate spaces going down to the bottom of the delam.
Using a large syringe. Inject the epoxy resin into the top holes until it starts to appear at the holes below.
Continue injecting and moving down the RV wall until the bottom holes are showing the epoxy coming out.
You can wipe off any excess while applying pressure to the RV wall. Then:-
Don't forget to put some plastic sheeting over the RV wall before placing the board.
Place the board and wedge with the 3x2 against the walls. Job done.
Not sure about the construction of RVs compared with Hobie cats (which I sail), but there is a product called Git-Rot which is commonly used on Hobie cats to repair delamed areas. As stated by others, very small holes are drilled throughout the delamed area and the product is injected using a dental syringe. The drilled holes only penetrate the outer layer of glass and mid layer of core material, but not the underlying layer. Must be very careful. At any rate, that method and product is used on Hobie cats. Maybe others can add insight as to whether it would work on RVs.
Git Rot is an epoxy filler/binder for rotted wood. Rot may or may not accompany delamination in an RV skin, especially now many RVs now have metal frames. The other piece of the problem in RV delam is simply that the fiberglass skin has detached from the substrate. Git Rot won't fix that - you need an adhesive to bond the skin back to the substrate and a means of clamping it there until the adhesive dries.
true most coaches now have metal frames but the substrate you speak of was either a laminate or less likely only foam ,delamination is usally from water intrusion which in tern causes the laminate to fall apart and loose it bond to the skin , I have successfully repaired areas using marine epoxy if you can find spot on the inside preferable high on the bubble you can inject epoxy with a syringe tru a hole to the bubble and it will bond! , sometimes you can take a frame or cover off from outside and fill the crack , for only a small soft spot a low viscous rot epoxy will fix the spot . For larger areas use a thicker epoxy such as alaminating / bonding epoxy , you drill from the inside a 1/16 hole for the thin epoxy a 1/4 hole for the thicker stuff the difference will be the syringe for large amounts use a large horse wormer type for the thin epoxy like gits rot use a syringe with the largest needle you can find , now for bubbles you will also need to pull your coach next to a house or structure where you can take a board ot adjustable paint roller pole and take a piece of plywood of appropriate size and put pressure on the bubble , guys or gals marine epoxy works if the RV industry built mare like the marine we wouldn't have these issues my favorite epoxy is system 3 but west epoxy or any marine grade will do the job gits rots is used on engine bed stringer repair its more than up to skins if I need to elaborate more I can I posted this to try to help and share my knowledge and experience other forums have relly helped me good luck
As per a previous post, some delam can be repaired by injecting epoxy, clamping etc. Check out Composet Products for special epoxies used for repairs. They also have a kit for injecting the glue.
Website is www.delamrepair.com
There are some repair pictures posted there as well.
I tented it over and kept it warm for 4 days. The clear coat is some very slow curing resin.
The results? I got a partial repair. The edge of the window was solid down about 4 ", but below that there was still a bubble; you can push on a slight delam like this and feel it.
I chose the System Three silvertip laminating resin and fast hardener for the next go. Now the edge was all glued up and I had no access to the bubble. I got out my telecom long bit and did some surgery. http://i810.photobucket.com/albums/zz29/skyking60/delamination/delam01.jpg
I measured out and drilled a couple of holes from above, down through the foam core at an angle to access the delam bubble. I felt the FRP skin and could feel the bit on the other side. I had to chew on that luan plywood to be sure i got epoxy past it, but not clear through the FRP. http://i810.photobucket.com/albums/zz29/skyking60/delamination/delam03.jpg
I used 1/4" tubing to get the resin down to the repair.
I used the same 4x10 and wedges, but left some gaps so I could monitor how I was doing. The failure on the first attempt was due to not getting resin in there, and also not getting the surface clamped properly. I could not see this with the wood and wedges on the first go. http://i810.photobucket.com/albums/zz29/skyking60/delamination/delam08.jpg
1) I would use the method of parking the trailer next to a wall and using sticks between the trailer and wall to get the clamping force. I had too much area for my method to work.
2) The faster epoxy is better. Easy to keep a good cure temp for a day, as opposed to 4.
3) do not use shipping tape to protect the skin of the trailer! Heated up, it was terrible to remove. Try anything else but that.
4) this is an absolute roll of the dice. No way to control the surfaces in question, check for contamination, etc. It may not work for countless reasons, or let go again for those same reasons. I will report back as a get some time on the repair.
It will likely never see the heat of the desert Southwest, but it will get to 100 around here. Heat is the main engine of delamination. Once it gets started, the heat cycles continue to break the bond as the two parts expand and contract at different rates.
Thanks Gary. It took time which I had more than money right now.
next up: roof replacement. I posted in a coating thread, but when I went up to fix the fantastic fan I found a fantastic 2' x 4' soft spot. Made a command decision to get new EPDM and do it right. I'll start a thread for that one mid-July.
All in all, a very nice job! I agree about it being a roll of the dice because there are so many variables. This thread, and all the details/pics you provided, will really come in handy for the next person who has to attack this. Good luck with the EPDM also.
Great Job. Should last.
I can add a couple of tidbits:
-Use a wax-based mold release compound instead of the tape.
-try Composet SLV epoxy (www.delamrepair.com) for the injection. It is specifiaclly designed to flow down inside the wall and set up in about an hour.
-polyurethane sealant has some good properties, may be better than silicone for sealing outside window frame
I think I am about to find out what the commercial body shop recommends by way of a fix, as my hit & run has caused some delamination on one of the compartment doors, and on one of the large upper panels. I'll let you know.