I'll start by saying my experience with fiberglass is minimal. I've only modified a fiberglass camper shell by slicing the front of the camper to better fit the profile of my truck cab, and I've done a few hole/crack repairs on modern car aftermarket front bumpers & spoilers, and some surfboard repairs when I was younger. I have a fiberglass one-piece front end for my '56 F100. This is an older one from US Body, but a pretty nice unit that was installed on a vehicle, but never finished or painted. I'd like to use this front end over my stock sheet metal front end that some asshole "welded" together for a one-piece front end in the 70's, but the glass one needs some work before I'd consider using it on my truck... First, there are basically fake hood to fender gaps that are about 1/8" deep and 3/16" wide. I'd like to make this front end appear to be as original as I can, so I'd like to cut that seam all the way through the fiberglass from the front edge of the hood, to the cowl, but I'm wondering how I should go about this without weakening the entire structure. My idea was to bend some sheet metal into a "u" or "top hat" shape running the length of the cut, and glass it in from the bottom side to help reinforce the glass at the newly cut hood to fender gap. If that would work, how wide should the reinforcement piece be? Second, the bumper bracket slots in the lower valance have filler pieces already in place, but they have big gaps that would need to be filled. I'd like to either fill the existing gaps, or cut out the entire slot area out and make new pieces that are, I guess "butt welded" flush. Would would be the ideal way to approach this? Third, I'd like to reinforce the hinge mounting points where the hinge attaches to the fiberglass. This is not a race weight front end, so it isn't light, and I don't want vibrations from the road to wallow out the mounting holes in the fiberglass. Can I simply glass in a metal plate, like 3/16" thick, that could be used to help spread the load/forces? This hinge attaches to the wind deflector area behind the grille. There are possibly some other small brackets and reinforcing struts that may need to be attached as well. So I guess my questions are really based around what materials to use to do these modifications/repairs? I don't want to use the wrong stuff that wont last, or will show up through the paint down the road. I want to ensure the materials bond properly and will last. I'm also curious if there is any reason not use to aluminum as the reinforcements over steel, as I'm not sure if there would be some chemical reaction producing hydrogen gas, like when aluminum and concrete are in contact. Tips are appreciated.
I'm no expert but look into the West systems epoxy product. They have filler powers of various kinds that mix with the resin and hardeners. I've used some of them. Wood bonds well, metal does not.
Resin and fiberglass mat are your friend, using metal or wood glued to any surface that is opposite of a surface that can be seen on the outside will print through when out in the sun. I hope that makes sense. Make sure you sand any surface with 36 grit that you are going to fiberglass to' You can make an edge using cardboard or some other stiff material covered with masking tape and waxed. This will allow you to remove the cardboard after you have laid up the edge with mat and resin. You can use a small amount of bondo to attach and hold the cardboard in place while you lay up the back side. I'm no expert but I've used this method many times. If you use metal to reinforce, make sure it isn't opposite and outside surface that will show. I have used 3m 08115 or 3m 07333 to bond metal to fiberglass it won't let go. On the bumper holes grind out the front side, apply several layers of mat then finish off with filler. Final note use mat and not fiberglass cloth as it will print through. I hope this helps. This is how I do it, I'm sure there are other options.
Sounds like a lot of work to me to make it seem more correct. I have done a lot of fiberglass work including making flanges on edges, etc. like you are thinking out of fiberglass. Not sure I would go to all that trouble if it were me. I could see you having a ton of hours in fiberglass parts that still appear to be fiberglass. I would rather find some old steel parts if possible. But, just depends what look you are going for.
It would be a lot easier and you would get much better results if you found a metal front clip and used that.
Paint the bottom of the seam a shade of black. You think most people are going to know all yours efforts or ask if those seems are real?
I have original steel front fenders & hood that were welded together (poorly) in the 1970's to make a one piece front end. I also have original steel front fenders and hood that are separate. All of those need so much metal work that I'd be better off doing simple modifications to the fiberglass front end to get the look I'm after. I can bolt the fiberglass front end on as is and it'll be fine. I just figure while I'm getting it prepped I might as well do some minor tweaks to make it visually better and physically stronger.
If you are committed to doing the fiberglass, I might be able to help with some advice. Between what I have done on vettes, making custom parts, and also how we approach fiberglass on the equipment that we design and build at my workplace, I might have some useful information. Shoot me a pm if interested and I could give you my number or something. For reference, I recently fixed a 55 Chevy front clip that should have never been fixed considering how many pieces it was in and how much was even missing. It would have been way cheaper and easier to buy new. But, the front end had been on that gasser since the 60’s, so I fixed it. I get wanting to do it the way you want.
I don't see much wrong with the style and how it looks to have separation between fender and hood. I see the angle iron is bolted to the fiberglass and the hinge attached to that, on my two fronts I just glassed in conduit and it's been holding up great for years. I'd have to better see the hinge and how it attaches to the frame to see what could improve the structural functionality of it.
I can understand wanting the hood to look separate. However, if you wind up putting metal under the hood to fender gaps, you will still have a one piece seam that can bee seen and as mentioned above, the metal reinforcement will eventually show through to the outside. Rather than using metal, add additional mat and cloth under the seam and use a router or Dremel to make the gaps as wide or deep as you desire. Putting a painted black gap in the recess should give you the effect you are looking for. If you use an airbrush you can feather shades of grey in to make the line less linear and more representative of shadowing. Next, the bumper cut outs. If you want to reinforce the hinge mounts perhaps you can incorporate a brace that comes over from the cutouts. Are you wanting the cutouts to be smooth and gapless or just more finished looking? It could be a way to install metal plates and glass them in behind the cutouts. When they eventually show through, they will blend in with the seams around the cutouts if you were going to leave seams. I personally would do a very narrow seam around them so they look like they were capped over and come off the back side to tie into hinges. You might move the hinges in a little to better line up with the frame that should be right behind the bumper cutouts. It would allow you to reinforce the hinges without adding too much extra work.
You should not use pure gelcoat on top of body filler. You need to cut the first gelcoat coat with patchaid. Read the instructions on the sales page. Guide coat and block sand. Respray more gelcoat if you sand through. Guide and block until your happy. We don't use primer. Spray color straight on the gelcoat. https://fiberglasssupplydepot.com/Gelcoat-Patchaid.html
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