I just cracked my hood just above the passenger wheel well, and just above the passenger side side marker light. These areas are the thinnest part of the hood I believe. I have done very good body work in the past on metal.

Anyone every attempt body owrk on their vette with good results. What products did you use? I would like to body work it. If I can;t get good results in the final finish, I'll let a shop paint it.

Thanks if you could lend some tips...

 

Close the hood on something? If it's just a small crack, v it out, use fiberglass reinforced filler such as Kitty Hair, to make the repair, than use your regular filler and high build primer just as you would with metal.

 

Not sure about the earlier-model C4's, but my C4 body is made of SMC fiberglass, a special type of fiberglass that is tricky to bond repairs to. Rather than repost my experiences with it, I will link you to this thread as it has lots of helpful information along with my own.

http://forums.corvetteforum.com/show...post1557671476

 

Hey brother. We have a new section just for this type of question.

http://forums.corvetteforum.com/forumdisplay.php?f=138

 

I dont remember where I saw a thread concerning a cracked hood caused by the end of the radiator shroud hitting the hood.(passenger side) Gordon Killebrew said he was aware of this and recommended to place some white grease on the highest edges of the shroud corners and close the hood.Open it up and look for the grease marks on the hood.File it down slightly to remove the stress on the hood.I would do this before any body work.
Good luck

 

Keep us posted on the progress of this thing, please.

 

In our shop the only products we use on SMC repairs and most repairs in general are either the DuraMix or 3M AutoMix products. They are the only true lifetime repair on SMC panels and are also very easy to use. On your hood you must determine if the damage is structural or superficial. If the cracks extend through the panel to the back side you need to make the structural repair. If they are simply stress cracks you will make a superficial repair. If you need to make a structural repair the steps are as follows.

1 Clean the panel front and back with a initial prep cleaner
2 Sand an area down to the SMC that extends approximately 2 inches from the crack on the front and back side
3 Bevel the top side of the panel from the crack to about 1 inch back; start at the crack and sand the panel down to a point and bevel it back into the panel like a "V"
4 Scuff the both sides of the panel with 80 grit paper and dust off (DO NOT use a liquid prep on SMC under any circumstances!)
5 Apply the line specific patch (either DuraMix or AutoMix) using the compound as a glue
6 Once that has cured (check label for time; it is quick) fill the trough that you created on the top side if the panel making sure to keep the tip in the compound while pumping to avoid bubbles
7 Once cured you can sand and begin bodywork

On a superficial repair you will simply skip work on the back of the panel and perform all of your work on the top side just as described above.
NOTE: If using DuraMix you can not apply body fillers directly, you must use more of the repair compound to fill. If you use the AutoMix you can apply your fillers directly. If you have any direct questions about this process DuraMix sells a very good video on who to do this or you can post them here. This is the best and really only way to repair these panels for the life of the vehicle; they will not pop loose or separate even in a crash, truly amazing stuff! Hope this helps and these products are available through any paint and body store and even some local parts houses.

 

Deakins,

I respectively have to dis agree. The DuraMix/ Auto Mix is not "the only way" to make SMC repairs. I use the "old school" way to repair the stress and/or structural damage.

Using the same methods to prep the panels as you do, I use 1 1/2 oz. fiberglass mat with Fiberglass Evercoat SMC Resin to make the repairs. If it's just a stress crack, I use Evercoat's SMC Panel Adhesive to fill the v'd out area on the front side. You can use regular bondo (although I prefer Rage) to finish out the repair. With this method, there is no need for buying an expensive gun. This has worked well for me the past 20 or so years.

I do use the DuraMix to install new panels on the C4's however.

My .02

Dan

 

Dan,

If you notice I wrote "life long" in that statement. What we have experienced with resin repairs (that we have had to work on or around) is not that the resin won't adhere to the SMC but that the resins become very hard once cured. A perfect example I have is a hood on a customers c4. It was repaired with mat/resin sometime ago before the current owner bought the vehicle. After a while the repair which is very hard and strong began to tear loose and crack the SMC around it. Essentially what he had was a very rigid, actually, too rigid of a repair and over time with the hood attempting to flex and the repair refusing to, the repair came loose. Now if the resin and mat you are using (which I have no direct experience with) better matches the structural properties of the SMC panels (which the Evercoat website does not address) it may not have this type of a problem and would avoid buying the guns. We just feel that the $60 for the applicator gun is well spent insurance that one of our $7000 jobs does not come back with a failed repair. So absolutely, the methods I listed may not be the only ways to repair SMC, but they are the only methods that we feel are truly for the life of the panel in that they precisely match the structural properties of the SMC. Have you repaired a quarter panel with your method? Was the repair able to flex with the panel or was the repair very stiff? I am curious and would like to look into this product but I am a little reluctant to try it out on a customer vehicle in the event that we would have a problem with it. Maybe a test panel off a car.......

Deakins

 

Deakins,

If your only experience with resin repairs is the one that you spoke of, then you don't know what kind of resin was really used in that repair. I agree, if the repair is made with regular ( as opposed to SMC resin) polyester fiberglass resin, the repair is doomed to fail. Most of the time, regular resin won't even feather out during the repair, it keeps peeling back. It's not that it's "too rigid", it just doesn't ad hear to the SMC, eventually it lets loose. The repair that you spoke of, in all likely-hood, didn't cause the SMC hood to crack. The cracks you saw around that repair were the ones someone was trying to repair.

When the C4's first came out, ( before Fiberglass Evercoat made SMC products) there was no way to repair those panels. I did some experimenting with epoxy fiberglass resin and mat to repair those first hits and they worked fine. The only drawback was the epoxy resin takes a lot longer to cure, and you have to maintain 65* - 70* for the first 24 hours or do the repair over.

To answer your question, Yes, I've repaired every SMC panel on a C4 at one time or another. I've never had a repair come loose or show up while using this method. I repaired one once, and a month later , the customer totaled the car. The panel broke about 6" on both sides of my repair, but my repair didn't crack. This was enough proof for me that my repairs we plenty durable enough.

Try it, you'll like it!

Dan