How to fill emblem holes correctly???

T

tonysturbo

I hope Bob Hollinshead will chime in on this one. I'm getting ready to fill the holes on a fiberglass header and want to ďo it correctly. My plan was to sand the back side with 80 grit out a ways from the holes and cover the top side with some release plastic, then fill the holes with gel coat first then mate the back side of the header with fiberglass mate that matches the mate in the header. Then remove the release plastic. From the top side and sand the gel coat to match the header. Then if needed add fiberglass bondo to make the body line on the header as needed. My question is, will this repair work good without having the holes show back up later down the line? Or have a better repair for the holes. Thanks IMAG0457.jpg
 
Or anyone else that can help. I just know Bob has a ton of knowledge. Thanks
 
Whatever you do, you need to grind and feather those holes way out on the top side. That will mean that you have to rebuild the center body line, there is no getting around it. Filling the holes with gelcoat from the bottom will not work, the repair will show.

That part is probably SMC. There's more than one way to fix it. The method I use is just to buy SMC compatible polyester resin like Evercoat 865, and use it with fiberglass mat just like you would regular resin. Some people say that polyester resin is junk, but all I know is I have not had a failure with this material.

SMC Fiberglass Resin.jpg

It is important to get the process correct. The way I was taught was to brush some resin onto a surface like a mixing board, lay dry mat down, then proceed to saturate the mat with resin using a paint brush. Only then should the pre-saturated mat be peeled off the mixing board and applied to the repair area (which should also be brushed until wet but not dripping with resin), and the brush used to push out air and excess resin with a tapping, not brushing motion. The result should be a repair that is fully saturated but not wet, and air bubble free.
 
SMC is the best. Expensive compared to the old stuff but well worth it.
 
I was also taught that when making pieces of mat to place in the repair area, it's just best to tear it with your hands rather than cut it with scissors, because that way you get a tapered edge to the repair instead of abrupt ledges. Make the first piece really small, just barely covering the holes, with each layer being just slightly larger than the last. Done carefully, this should fill in your beveled and feathered area until the repair area is fairly close to the right contour so lots of grinding won't be necessary.
 
This is what i have already. So if i stuff the hole with the evercoat resin and mat together after i grind the area on top out some and the back and mat and resin the top and bottom after that will that work? i would still use the USC gel coat on top of that after it dried so i could sand it with 80 grit so it will stick good. Then if needed i would still use some evercoat short tiger hair bondo to make the body line as needed. Will this work guys? Thanks for the advise everyone. They do not have the SMC here in Battle CreekIMAG0470.jpg
 
The normal fiberglass resin will not adhere properly to SMC. I'm sure that a reputable jobber that supplies knowledgeable body shops will have an appropriate product. I recommend you return the resin that you have. The normal use for gel coat is for application to a mold in the process of making new parts. There really is no need for it in a repair like the one you are planning. Also, I don't know if that gel coat would adhere to the SMC or not.

I want to mention again that no matter the repair material used, ghosting of those holes out in the sun is pretty much a given unless they are beveled and feathered way out.
 
Grind back the edges of the holes on both sides, use the smc compatible resin and matt layered up to fill the hole. You could use the resin you have if you applied two coats of epoxy primer first-it does work for repairs like this. Tapering the edges of the repair area well does two things: It provides a larger surface area for the repair materials to adhere to and it also feathers the edge of the repair area so if there's a slight difference in expansion and contraction it won't show. With glass or smc you never want to fill a hole or do a repair without tapering the edge of the repair area.
 
What is SMC fiberglass. The part came from Gbody parts. I think Danko makes them for them. It has a white gel coat over the fiberglass mat. I just want to make sure its SMC and not something else before I proceed. Thanks.
 
I've copied these description from the Zip Corvette site. Their information is Corvette-related but I think it applies to your part as well. Here's the link: http://www.corvettepartsblog.com/corvette-restoration/corvette-restoration-tip-body-panels/

SMC Panels – 1973-1982 Corvettes were assembled of panels made from a sheet molded composite (“SMC”). SMC panels are formed by a high-pressure mold compressing a mix of fiberglass, resin, catalyst and release agent. SMC pieces are smoother than press molded fiberglass panels and have a marbled appearance – typically gray in color. Note SMC panels require special adhesives for bonding.

Press Molded Panels – 1968-1972 factory fiberglass panels were produced in molds that created an exceptionally strong part that were smooth on both sides. Original panels are black in color and do not have a gelcoat surface.

Hand Laid Panels – Replacement fiberglass panels are built by layering fiberglass mat and resin into a single mold. Construction of each piece begins with the spraying of gelcoat into a female mold; once cured, alternating layers of fiberglass matting and resin are hand rolled to eliminate air pockets and ensure an overall uniform thickness. Once “popped” from the mold, panels are hand trimmed and ground to final shape. Hand laid panels have a smooth exterior and a rough fiberglass/resin underside.

Tony, Check the back side of your header panel -- you might have a hand laid panel.
 
I think those original GM header panels from the 80's were all SMC, but your replacement aftermarket part may very well be fiberglass! Call the supplier or grind back the repair area and post up a picture-if it's got white gel coat then I bet it's regular glass. The backside would also tell-does it have a really rough looking finish like it was made with a glass hopper/gun?
 
The part had the marbled appearance of SMC to me, and the year of vehicle would indicate SMC as well. But all bets are off with an aftermarket piece.

I will say this, with the SMC compatible resins, you can repair both fiberglass and SMC successfully, which is why we stock it exclusively for repair work.
 
Bob Hollinshead;16352 said:
It says in the parts description hand layed fiberglass: http://www.gbodyparts.com/product_info.php?cPath=46_22_43_45&products_id=71&osCsid=79ab27738b27c35c48ae4666070dee12

so you can use the regular polyester repair materials that you have, no problemo!
Click to expand...
Thanks Bob,
The one i got from them is a all white one without the black gel coat. I left a message to find out for sure if it's the hand laid one or not. I took a better picture of the holes and you can see the mat that i had sanded into some. The back side is pretty smooth like the top is. I just want to make it right the first time and don't want to redo it later down the line. Do you have a number i could call you when i find out what it is for sure Bob?IMAG0477.jpg
 
1984-87 Turbo T-Type regal Header Panel $275.00



Standard T-Type header panel. This is a fiberglass piece.

This item DOES NOT come in the black gelcoat finish shown. It has a white finish. This unit has the 3 mounting holes in order to mount the header panel emblem. This piece is one of the best units out there for fit & finish. Extremely close to your original. We have found for the best possible fit is to remove the steel support from under the header panel. Use your original steel piece from your cracked header panel. Once this is done there is virtually an exact GM fit.

Thanks everyone for the help. This site is the best. Looks like i will be able to use the mat and resin i have already. I will not be using the USC Gelcoat.
 
If the inside of the part is smooth, and you can't see the fibers of the mat or chop, it is very likely an SMC part. Your picture looks a lot like SMC to me. Keep in mind that your supplier is probably just a reseller, and may not know exactly what the part is made of. Most average people have no idea there is even a difference between fiberglass and SMC, and of course SMC contains fiberglass, it's the resin technology that is different.

But it's not hard to tell that you really just want to use the product you have, so I hope it works out for you.
 
Im like crash. Just stock SMC resin.and no worries.. I once used fiberglass resin on SMC without epoxy.. Can u say bubbles and started peeling off months after finished. Same thing with Rage Gold Filler.. Never again!!
 
Just to be on the safe side i bought a Qt of the SMC that way it won't matter. It will be here tomorrow.
 
You must log in or register to reply here.
Back
Top