Polyester Won't Work On This Car...

[Brant Halterman]

Alex, Maybe this will help: The 15 x 6 Torq-Thrust "D" currently available from American Racing Equipment has a 3 5/8" backside setting. The 15 x 7 has a 3 3/4" backside setting. I'm not sure how this compares with the measurements on an original wheel. You may also be interested in the fact that American now makes a fully polished Torque-Thrust called a Torque-Thrust II. This differs from the regular Torque-Thrust in that it is a two piece alloy wheel and it is fully polished(looks like chrome.) The 15 x 6 has a 3 3/8" backside setting, but this wheel is available with custom ordered backside settings. Short polished aluminum caps are also available with the Corvette Crossed-Flag Logo-really nice. No-I don't work for American, but I own a Mustang Parts Business, and we sell lots of these wheels for early Mustangs. They were originally installed (in magnesium, not aluminum) on '65 Competition Model GT-350's.

[Chuck S.]

Polyester Won't Work On This Car...

Rev,

Since his body panels are SMC, he has to use an epoxy-based resin made for SMC.

Chuck Sangerhausen

[Dale Pearman]

That's Right!

When Corvettes were dropped from GM production the replacement two-seater DID use a sheet molded composite. Epoxy IS the thing to use! (I guess) Sorry for the dyno-sewer information!

Dale.

[Chuck S.]

What The Devil Happened...

Rev,

These posts aren't doing Eric any good up here. You deleted your post didn't you? And, that gave the server brain cramps.

I wasn't kicking your shins; I thought your technique was good information, but the resin needed to be the right one. My understanding is that epoxy based resin can be used on ALL types of fiberglass, but polyester resin will only stick to polyester based fiber glass.

Chuck Sangerhausen

[Dale Pearman]

I Don't Want To Mislead Anyone

with incorrect information so I deleted the post. A caffiene drip with the IV has been started so soon the brain will work again! (I hope)

Dale.

[Eric Christie]

Re: Polyester Won't Work On This Car...

Thanks for the help. Now does this mean Duraglass is OK, or should I use another type of filler after I seal off the bottom . A brand name will help if you know and like one. Sorry, these threads have me confused.

[Chuck S.]

Fiberglass Repair

Eric,

Sorry for the confusion. It's all the Rev's fault.

Actually, I have not tried George's Duraglass technique; in fact, I have not personally done a repair on SMC. The repair technique I am familiar with is what Dale suggested in his deleted post for pre-73 polyester fiberglass, but I believe it will work the same on SMC except that you must have resin that is compatible with the SMC.

The first step is to record the location of the antenna hole. If there is any of the original hole outline remaining, use some heavy paper or cardboard to make a template to locate the antenna hole relative to some fixed references like the rear window and the fender peak line. On earlier shark cars, the antenna hole was 15/16" diameter with a 1/8" hole (semicircle?) on the rear edge of the larger hole. This small hole receives a locating peg on the antenna base.

The following assumes the hole is broken out all around, and that the hole will be completely covered and re-drilled after the repair is completed. If the hole is NOT broken out all around, you may be able to reduce the extent of the repair accordingly.

Taper grind the edges around the hole starting 2" from the hole and tapering the thickness down to zero thickness at the hole edge. Cut three or four pieces of 1 1/2 once fiberglass mat (not cloth); the first layer should be just slightly smaller than the size of the ground area and each succeeding piece to decrease in size about 1/8"-1/4". Mask off EVERYTHING you don't won't resin to get on creating more finishing work later.

You should apply a waxed (Johnson floor wax), slick back-up surface (aluminum, formica, plexiglass) on the under side of the deck. Since you also should repeat the lamination process on the underside, you will probably need to drop the spare carrier and the tank to allow access. Mix the resin, and use cheap throwaway "chip brush" to saturate the first mat layer, then apply it to the ground area. Use a fiberglass roller to roll the lamination eliminating excess resin and air bubbles. Repeat this lamination procedure with succeeding layers.

After the top surface has cured, repeat the above process on the underside of the deck. The top surface is finished by carefully grinding the cured lamination JUST BELOW the deck contour and applying a skim coat of body filler, which is then finished to contour.

This is the way the books say to make a repair. More than you wanted to know I am sure. If you want to read more, I recommend "Eckler's Complete Guide to Corvette Fiberglass Repair" sold at the NCRS store.

Chuck Sangerhausen

[Juliet P.]

And Urethane adhesives...

...are made for those cases where you need to bond fiberglass to SMC. There are also variants which will work between metal and SMC. Greg's and my understanding is that epoxy won't stick to SMC. Epoxy will work on fiberglass with either epoxy or fiberglass resin, but not SMC. Anyways, McMaster Carr sells the Lord brand adhesives which he'll be using to reglue the bonding strip seams and put the fiberglass doubler in the nose of his '65. Just thought I'd thrown that into the discussion. ~Juliet

[Chuck S.]

For SMC, I Only Know What I Read...

Juliet,

I didn't mean to imply that you could get away with using a generic epoxy resin from Home Depot. The chemical basis of the resin is probably more information than needed to be posted; for SMC repairs, I would seek out and buy materials recommended for SMC repairs from a reputable auto body supply or Corvette vendor. The important point is polyester resin WILL NOT WORK on SMC.

Your information that epoxy is incompatible with SMC is, as I understand what I read, incomplete. As you said, there are several different adhesive systems for SMC. In Eckler's catalog, I count three: one for SMC panels to bonding strips, one for SMC to metal, and the third system that has a redundant panel bonding adhesive that is epoxy based.

This adhesive is listed in a different part of the page from the first two adhesives, and the section includes a resin (Item 10698) and a body filler (Item 10701). This section is captioned "Other Repair Materials for GM's Sheet Molded Fiberglass (SMC)". The first item in this section is "Epoxy Bonding Adhesive", which is described as follows: "Manufactured by Lord Corp., Fusor Epoxy is ideal for general repair and bonding of SMC fiberglass. Two-part mixture. Item 27281. 2-Quart Unit. $39.95 kit" I PRESUME the following resin and filler are also epoxy based, but their chemical composition is really irrelevant so long as they are compatible with SMC.

The other (urethane?) adhesives are probably later developments that may offer advantages or characteristics of which I am totally unaware. Sorry to be so long-winded.

Chuck Sangerhausen

[George Daina]

FiberGlass Evercoat......

makes panel adhesive, resin, and other products specifically for SMC panels. Use the correct product for the panel intended, you won't have any problems, use the wrong product, expect to re-do whatever you did. You can get the correct products at your neighborhood automotive paint and supply store.

[George Daina]

Duraglass is the right product....

you won't have any problems. I used it as a filler when I fixed the hood edges on my 68.

[George Daina]

One more thing about DuraGlass.....

cover yourself, wear long sleeve shirt, tape the sleeves, wear rubber gloves, if not, the small glass strands will be airborne when you sand, and IT WILL DRIVE U NUTS with itches, but this stuff is like granite when cured. You WILL have to use a catalyst primer to seal it, as regular primer does not stick to DuraGlass, UNLESS, you apply a very thin coat of BONDOOOOOOO...use the catalyst primer.

[Ron De Vries]

Re: Fiberglass Repair

Im not sure about the newer style of glass your all talking about but on the 67 im working on I have been using un-waxed resin, as it is easier to apply another coat of glass over your first layer with the used of an acetone. As for a fill Chuck was speaking of, I have been using Mircospheres(powder) mixed with waxed Gel coat(available where you will get the rest of your supplies).It is very easy to sand and impervious to water. Dont fill you panel with this, it is only a light filler not a panel builder.

[Chuck S.]

Re: Duraglass is the right product....

George,

Check back with us in five years, no, make that ten years, and give us the report on how "Duraglass's Mt. Rushmore" (granite, get it?) is holding up.

Chuck Sangerhausen

[George Daina]

Chucky....I can do that right now......

how about 18 years of Dura Glass? Way back when in 1983, a 81 arrived at the local bone yard, rear pushed all the way up the passanger's seat, the front was untouched but it broke loose from the bonding strip by the cowl, so, a friend with a 69 decided to upgrade the front clip to a 81, what a job of fabricating and fitting and grinding, and glass and resin, and after everything was in place, Dura Glass took over and we used it over all the areas that we worked on, and to this day, no cracks, we used Feather Fill in lieu of Gel Coat. Actually, the last time I saw the car was last year, just before it was sold and the guy purchased a 93 40th.

So, now, YOU KNOW the rest of the story, and yes, I did use that stuff on my 68 and have all the confidence in the world it will look in 20 years as it looks today. I think I'm gonna buy some stock in that company......