I want to use a dremel to put an image into the hood. I will probably recess not more than an 1/8”. Am I asking for trouble? I am not sure what I should use as a filler if you will. I am not going to bring it back to flush.
You weaken the skin face by Cutting can, likely will, cause problems later because gives more flex to the finish and the skin face. Plus hood is a safety feature with latch bolts at rear corners and a "fold zone" on bottom so won't get push thru windshield in a wreck. Weaken hood may not fold properly in a wreck. ETA--> or may fold just for opening/closing the hood very soon or down the road depending exactly how you cut.<--
CLICK FOR FULL SIZE
YT Fiero Crash Test to watch several front end wrecks.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
If your intent is to recess a graphic in the surface of the hood, but not cut all the way through the hood, then you will want to stick to about 1/32" recess.
1/8 will cut through, 1/16" will likely make it too thin and prone to cracking. 1/32 will be visible, but still leave material under it for hood integrity.
The front hood is SMC, similar to fiberglass. If there are any cracks in the paint or sealer, moisture can get into the fibers and expand them over time, so the paint job has to be very good to prevent blisters. On a show car it might be OK, but if your car sees a normal amount of water, chances are good that paint will lift after a few years. Here is a photo of the problem on a Fiero sun roof.
That too... Above hood had iffy factory paint that blistered etc after ~ 5 years much worse after 30 years. Roof has damage at SR edges too because easy to wreck the edges taking the roof off/on.
If your intent is to recess a graphic in the surface of the hood, but not cut all the way through the hood, then you will want to stick to about 1/32" recess.
1/8 will cut through, 1/16" will likely make it too thin and prone to cracking. 1/32 will be visible, but still leave material under it for hood integrity.
1/32 would be hard to use the SMC to seal the graphic without completely filling the graphic back in completely. I will have a scrap piece to test out eventually, I have two hoods but I don’t want to ruin either the of them. Thanks for the info guys.
Um... what is wrong with doing it the way I want? Did I not ask for people opinion of what would happen? Why do what every one else does?
Then it sounds like you are blazing the trail. Go ahead and give it a go and report back how it turns out!
There is nothing wrong with doing things the way you want but there are reasons certain techniques are common and others are not. Hand carving a fiberglass hood doesn't seem like something that will yield any sort of good result to me but I'm happy to be proven wrong!
[This message has been edited by thedrue (edited 03-29-2019).]
To do it correctly (i.e. without trashing the hood), you would need to separate the two layers of the hood, build up fiberglass on the backside of the skin, then reattach the bottom layer to the skin. I would also suggest making sure there are no sharp corners in your cuts, because the SMC material is prone to cracking.