C4happy

I am working on a 90 vette hood the gelcoat is spider web type crack after sanding I have a 1/8 inch hole that need to fill I was going to use this stuff called Duraglass but I was told that it wouldn't stick and to use resin is that the best to use??

929nitro

Yes you want to use epoxy based fillers. US Chemicals, who make the Duraglass also meke a product called ProGlass which is SMC approved. I am working on hood mods for mey sons 90 and have found this product easy to use. I filled in the emblem holes but used some glass mat first then the filler.

kaiserbud

I am just getting back into the paint/body train of thought after 30 years. Technologies have changed and to be honest, I cannot recall which 'bondo' we used back then. BUT - when we filled the cracks with fiberglass we FILLED them almost perfectly with glass and the minimal topcoat of filler that we used was just that - minimal.

In getting caught up, I contacted a local well known Corvette shop and they advised to use Clauplast. It works well, but it could be a bit less runny. I believe these are the same guys that make Z-Chrome

929nitro

You just need to make sure that the fiberglass resin is an epoxy resin and not the standard fiberglass resin you get in most kits. When I was putting the louvers on the 90 vette my local body supply house sold me the fiberglass and resin which I used and then after reading various posts on this forum I went back and tugged on the glass. Came off like a perfect mold. Mid 70's on up use SMC panels which has a mold release agent that does not allow the fiberglass resins and polyester based fillers to permanently bond. I learned the hard way by doing before reading and then had to redo everything.

kaiserbud

hmmm. - I thought SMC was put into production in 1981 ???? I know that the panels at least up to 1974 were not SMC.

I think the fiberglass popping out might be due to not preparing teh glass correctly and/or not the proper amounts of hardener.

929nitro

SMC is on 74 on up. Fiberglass problem occurred on the 90 vette I was working on.

2000FRCZ19

you can use epoxy resin with glass or you can use evercoat fiber tech. both are smc compatable and will work well. i have been using the fiber tech on my project and really like it.

kaiserbud

Dick - thanks for the info - guess this post offers support:

http://forums.corvetteforum.com/c3-g...mc-panels.html

929nitro

I agree thats the only way we learn.

BLOWNBLUEZ06

GM approved SMC and fiberglass repair. Don't know if you can get it in the U.S. though.
http://www.lord.com/Home/ProductsSer...1/Default.aspx

JackDidley

Lord Fusor SMC products are tops. I used their adhesive to bond the back half of my C4 together a few years ago. When someone hit me in the 1/4 last summer the panel crumbled but stayed put where I bonded it.

wombvette

ACTUALLY, `71 rear fenders were the first SMC, Replacing an earlier form called Genite that was first used on `69 doors.

kaiserbud

Actually, the bonded area (if done correctly) is absolutely stronger that the panel

BLOWNBLUEZ06

shamdave

I have some low spots in my door and on my quarter panel. do i use a bit of bondo? what do you use for small low spots?

Scott Marzahl

Hey guys,
I hope Wombvette chimes in but be careful when using products listed as compatible with SMC such as ProGlass and Evercoat products. They are STILL polyester resin based products with a little additive in them that is supposed to help them bite into SMC. Also note on the directions, these products require that you grind your panel with 24 grit to help get a mechanical bond. For the amount of work that goes into body work and paint, the last thing you want is filler coming loose.

Make your repairs using ONLY epoxy resin and mat. Then either mix up some fairing compound (West Systems) using your epoxy resin for your filler, OR spray your repair area with a couple good coats of epoxy primer. Then scuff the epoxy primer with 80-120 grit and use your favorite polyester body filler like Rage, Marson Platinum etc. directly over the epoxy primer and you should be worry free.

Wayne, care to add anything else?

Scott

samsonb

Any update on this? I need to repair a hole/crack in the front left corner of the floorboard on my 89.

Inside:



Outside:





And which Lord products were you refering to in that link? I'd like to do an easy repair. I know alot use the resin soaked cloth. But I wondered if the Lord stuff has anything I could just smear over the hole and crack?

wombvette

You covered it pretty good Scott. The SMC compatible stuff is usually fine on the surface where there is no real stress on it, but I wouldn't use it on any bonding or structural job.

porchdog

in the future i will make my own filler with epoxy resin and mat. on the last car the only ghost that showed when buffing were smalll areas of duraglass . there will never be any polyester in my shop again. it is thermal reactive and i believe it is the number one problem we are having with the c1-c2 cars because of the age of the glass. polyester is for shirts

samsonb

What would be good to use to repair a hole/crack in the flooboard of a C4? I did see some of that Evercoat SMC stuff in a shop down the road.

And what kind of grinder are you guys using to cut out the hole and cracks?