How to Fix Fiberglass from the Front?

[morbank]

Hi All-
Tried to post on an older thread but didn't get enough info, so I'm posting to a new thread.

After a camping trip this weekend we will have 5 weeks to paint the outside and inside of the Scamp. We need to fix three problem areas where the fiberglass body was damaged. We will replace a rear area behind the bumper where we can access the fiberglass from the rear. But in two other areas, we can only repair from the front.

I'm attaching pictures to see what you best think we should do. We have watched many videos but they all repair damage from the back. We CANNOT repair from the back! Furthermore, must we apply gelcoat to these areas if we are planning to prime and paint the entire body anyway?

Basic step by step instructions would be most helpful of course!! Thank you for your time. -Cindy

This damage is just chipped away fiberglass:


This damage is an actual dent. I'm hoping not to have to cut away the material because we cannot repair from the back.

[David Tilston]

I have never done this, but my neighbour who builds cargo trailers and small dump trucks in his back yard described this procedure to me. He also works with fiberglass. He picked up a small, old, fiberglass, class C motor home that had been run into a low bridge. When he was done, you could not see any evidence that it had been damaged at all.
Remove all damaged material. Leave no cracks.
Thin the shell around the hole gradually till you reach the inside surface. the hole should be framed by ~2-3" of feathered shell. If you could get to the inside, the inside surface would ideally also be feathered, but that is not an option in your case.
paint on resin to the feathered parts. Apply resin soaked fiberglass cloth accross the feathered parts, and the hole.
Sand it down till it is smooth.
If there are still low spots, then apply more resin soaked cloth, then sand. Repeat as required.
A good two part paint is essentially gel coat, so no under coat is required.

[Dave Fish]

I have glassed a kayak and had a similar repair done professionlly on my Casita. I think David's process is good.

I started using a polymer, I think, glass on my kayak. Could not sand worth a darn beacause it gummed up the sandpaper. It is suppisedly more flexible. Switched to System 3 and got an acceptible finish.

One big lesson learned is watch your temperature. If it is too cool the FB will not set properly.

[Roy in TO]

As David said, adding in ...
When you lay the fiberglass, start with a smaller piece over the hole gradualy increasing sizes as you near the outer surface. Remember your prep area will be tapered down to the damaged area.

[D White]

Originally Posted by David Tilston

I have never done this, but my neighbour who builds cargo trailers and small dump trucks in his back yard described this procedure to me. He also works with fiberglass. He picked up a small, old, fiberglass, class C motor home that had been run into a low bridge. When he was done, you could not see any evidence that it had been damaged at all.
Remove all damaged material. Leave no cracks.
Thin the shell around the hole gradually till you reach the inside surface. the hole should be framed by ~2-3" of feathered shell. If you could get to the inside, the inside surface would ideally also be feathered, but that is not an option in your case.
paint on resin to the feathered parts. Apply resin soaked fiberglass cloth accross the feathered parts, and the hole.
Sand it down till it is smooth.
If there are still low spots, then apply more resin soaked cloth, then sand. Repeat as required.
A good two part paint is essentially gel coat, so no under coat is required.

I would use mat instead of cloth for easier finishing

[David Tilston]

Mr. D White is correct. Mat is what I meant, just not what I typed.

[rhkirkham]

Cindy
I fixed multiple holes and cracks on my old Boler. I used woven mat rather than the non-woven (looks like a birds nest of short fiberglass strands all laid willy-nilly) because I thought that the woven would be stronger. You can get kits that contain all you need from home depot. (mat, resin and hardner) Just get rubber gloves and dollar store paint brushes. If it is hot out work in the shade. (heat makes the resin set up quickly) Sand the area so that the fiberglass bonds. Pre cut the mat to fit. Mix the resin. Paint it on the sanded area. Place the mat on the resin. Paint the mat with resin so that the whole mat is soaked. Wait 10 minutes for it to set up. May be less depending on tempurature. Sand smooth all drips and bumps. I used Bondo to smooth out the edges. Paint and you cannot tell. The body on my Boler had a 5" square hole for the furnace, a dinner plate size area that was cracked, cracks around the door and various cracks at the bottom. Now everyone says the body is excellent. (see my profile picture) sorry I did not take before pictures. This is easy work, but sticky. Don't forget to wear a mask when sanding. If you have specific questions - PM me.

Rick

[Thomas G.]

One tip - I use disposable Dixie cups to mix the resin and hardener. It makes it easier to mix the proper ratio and when it hardens, just toss.

[Roy in TO]

Margarine and yogurt containers work too.

[Dave Fish]

A bag if popcycle sticks works great for stirring. We used the cheap foam brushes for applying the epoxy

[Bob Miller]

You didn't show us any scale to indicate how big the damaged areas, but I have frequently just sealed and then covered minor damage areas with 3-4 inch round plastic vent covers. They always look like they belong where ever you put them, damage repairs don't always come out so well.

[Harlequin]

Originally Posted by Roy in TO

Margarine and yogurt containers work too.

careful with that one, though! I had fiberglass dissolve\eat through a yogurt cup before.

[freddo411]

Ziploc containers:
Food - Non-Food - Containers - Organization - Ziploc® Brand Containers

When you are done, and dry -- squeeze the deform the plastic and the resin comes out entirely. Ready for the next mix.

[Roy in TO]

The rollers used to get rid of air bubbles and level your glass are a great help.

[RogerDat]

This link has some good step by step with pictures of different types of fiberglass repair. Has examples of doing the types of repair you have. Aimed at boats which is the major market for westsystem products but FG is FG. Good luck.


http://www.westsystem.com/ss/assets/HowTo-Publications/Fiberglass-Boat-Repair-and-Maintenance.pdf


Have not personally used it but some of the body fillers are fiberglass stranded, have read posts of people using them as a "finish" coat, seems like they might feather in better when sanded then resin and may be a better match for the texture of the outer gel coat. When filler was used over lead body work one used a rougher sandpaper on the lead so the thin filler coat had scratches to bind to. YMMV.

Oh and drilling small hole at end of crack will help terminate it.

[morbank]

Originally Posted by Bob Miller

You didn't show us any scale to indicate how big the damaged areas, but I have frequently just sealed and then covered minor damage areas with 3-4 inch round plastic vent covers. They always look like they belong where ever you put them, damage repairs don't always come out so well.

The first image of damage is about 2" long. The second and larger damage is about 3" long. They are both on curved sections of Scamp so I don't think a vent cover will suffice. But thank you for the suggestion!

[Bob Miller]

I don't know of any curves on a SCAMP they can't be fit around. Add an extra screw between each of the three original and you will be set. There are also small vents that can be used as a cover-up.

[Kenny D]

I am in a similar situtation with an RV I am restoring and have been on a big learning curve. The west systems vid was good.I had watched it a few week ago. I also have one spot I cannot get to from the back. I was told to taper it out about 3-4 inches and fill back in. The only things I will add from my research (and I have not used it yet but plan to try it) was that SMC Resin seems to be the strongest and will bond to anything. Also for filler I was going to try Evercoat Vettefill.
Again I am not a pro and this is only what I have read. I am in the process of trying it myself.

[morbank]

We are going to start on the fixes tomorrow. Since some of the damage is very shallow, do you think we could skip the step of adding fiberglass strips/cloth and simply using fiberglass filler/bondo? All of the videos we've watched stress using fiberglass cloth to maintain or add strength, but the areas with the damage are not substantial. I don't think they necessarily require "extra" stability like you would need on a boat or car bumper.

[Thomas G.]

Originally Posted by morbank

We are going to start on the fixes tomorrow. Since some of the damage is very shallow, do you think we could skip the step of adding fiberglass strips/cloth and simply using fiberglass filler/bondo? All of the videos we've watched stress using fiberglass cloth to maintain or add strength, but the areas with the damage are not substantial. I don't think they necessarily require "extra" stability like you would need on a boat or car bumper.

I would not skip the step of adding cloth or stands to the patch. You will have thermal stresses, if nothing else, and it will crack there. It really isn't that hard to do the cloth and you can finish it off with bondo if you prefer.