Homemade Fiberglass Fenders

After coming to realize that no one has a pair of used fiberglass fenders ready to give up, and that the going rate for a pair with shipping was out of my reach, I decided to start from scratch and try and make my own. The results so far are a lot better than I had thought possible. Its a simple yet time consuming process to make anything out of fiberglass.

What I did to make the fenders:

1) Pulled the fenders off of my '71 and examined them for rot holes, dents, and anything that looked bad. The fiberglass will show all of these things when it is laid out.

2) I used masking tape to cover up any rot holes from the outside, and any attachment holes from the inside. I knocked out the dents and stretched tape over the remaining smaller dents form the outside.

3) Having accounted for all dents, attachment points, marker light, and rot holes, I proceeded to wipe down the fender with a wax and grease remover. This took away all debris from the road; dirt, tar, road salt, etc.

4) Using "Meguires Cleaner Wax", I coated the entire fender with wax. The wax will act as a mold release, as resin and fiberglass will not stick to it. Very important to do this step and make sure that all parts have been coated thoroughly. (ask me how i know! :whistling: )

5) I then cut down a sheet of fiberglass matting to roughly fit the fender. I made sure it was over sized so the entire fender would be easily covered. With the layer of fiberglass laid over the entire surface of the fender, I mixed up some resin and began soaking the fiberglass. When the fiberglass is soaked, you will be able to have it stick to most angles, as long as its not upside down of course!

---It is important to note that you cannot do the entire fender in one shot. If you were to glass in the area where the front trim or the top area where the fender attaches to the apron, you'd never be able to pop the fiberglass off of the fender!-----

6) I let the fiberglass sit and harden overnight. (you can heat it for speedier drying and curing times) I then cut the excess fiberglass off using an air saw, cutting exactly around the edges of the metal fender.

7) I was then able to free a portion of the fiberglass off the metal fender. I blew compressed air into the gap between the metal and fiberglass surfaces , freeing the rest of the fiberglass from the steel. (this is where the wax preparation comes into play)

8) Walla! I now have an outer fiberglass skin for my fenders!

The next step is to reinforce the fender. I will apply 2 more layers of fiberglass matting to the INSIDE of the fiberglass shell to give it a stiffer structure, and then I will use fiberglass cloth strips for further bracing and in the areas of mounting holes.

When that is dry and formed, I will sand the external fiberglass down smooth with 80 grit sand paper, and then shoot the fenders with a hi0build primer to fill any sand scratches. The fenders should weigh approx 24lbs as a pair said and done. A big improvement over the stock weight of 50lbs each!

Here are a few pictures of the process:

Nice Job!!

2 things to make your life easier when doing this type of work

Pva

http://www.fibreglast.com/product/PVA_Release_Film_13/Mold_Releases

& Mold release

http://www.fibreglast.com/product/Parting_wax_1016/Mold_Releases

The only problem I see is that your part is now what ever thickness your layup is larger than the original..A much better way to do it (I have molded many fiberglass parts) Would be to use mold wax, pva ,then spray a gelkote on that..then do your layup & use that (what you have now) as your mold where you layup the part on the inside of what you have now this way your dimisions are right on. Then you could make as many as you want & sell them to us here

I was originally thinking of making molds, but do to a lack of space to store the molds I won't be able to to do that. The size is a layer of glass thicker than it should be , but after sanding it'll only be a half layer too thick. So I think I can get away with slightly shimming the doors out and then the fenders out a little bit to fit the hood with proper gaps. I went into it knowing that and told myself Ill make due with it!

Thanks for the links to the release agents, they sure would have made the fender removal easier! I think I'll have to order some for the 1/4 panel scoops I'm making, I want to definitely mold those!

This was a big learning experience truthfully, and I'll be sure to change a few things the second time around!

Very cool! It's great to see all the effort and skill people are putting into these cars!

I was originally thinking of making molds, but do to a lack of space to store the molds I won't be able to to do that. The size is a layer of glass thicker than it should be , but after sanding it'll only be a half layer too thick. So I think I can get away with slightly shimming the doors out and then the fenders out a little bit to fit the hood with proper gaps. I went into it knowing that and told myself Ill make due with it!

Thanks for the links to the release agents, they sure would have made the fender removal easier! I think I'll have to order some for the 1/4 panel scoops I'm making, I want to definitely mold those!

This was a big learning experience truthfully, and I'll be sure to change a few things the second time around!

Click to expand...

Here's a tip to make your sanding & finish work easier...Doing it the way you are...Instead of using fiberglass mat for your first layer use fiberglass cloth

http://www.uscomposites.com/cloth.html

I would go with the 7725 at the minium you could go heavier ...you do 2 layers the second layer should be laid out at 45 degrees to the first...you can then make a simple support out of 1x1 or 1x2 pine strips to keep the shape of the fender (tack glue using a hot glue gun or super glue) the supports to the layup Before you pull it from the plug (your fender) Then do your fiber glass mat on the inside..This way you will have a smooth outside surface that just needs to have the weave filled..a bunch less work !!! Also you can dust the fender or glass with 3m spray adhesive so you can tack it to the fender helps keep it in all the compound curves & lay flat so there will be less air bubbles

Nice work, I have pondered the idea of making a hood for years. So I can use the tunnel ram in my picture.

An impressive undertaking, and an impressive result. Nice work.

Mark

Great job. Don't think I'd have the you know what to try that. Looks real good. Thanks for the post and pics.::goodjob::

Jim

I didn't realize you made them, I thought you just repaired them.. Nice job!

Awesome job. bravo. AS posted above I don't think I would try that myself hahaha::goodjob::

Well done! Keep us in the loop as you think about future projects.

Doc

thanks for the kind comments and helpful ideas on making my next fiberglass projects! A few buddies saw some of the pictures of the fenders and want some parts made up too. Going to be making a set of fenders for a buick wildcat, and then a custom hood for a 71-73 mustang with a built in cowl. (that is different than the dominator style hood!) The hood may be made into a mold, I'll keep that updated as the time comes around! I am also making the trunk lid for my car, and I've been considering making fiberglass 1/4 panels, but that idea is still up in the air!

i say stop, use mold release on the back side of the fiberglass piece you made, and lay new fiberglass inside the first mold. it will solve the issue with the parts being oversized and also give you a smoother finish since your base is off the original fender.

less body work, better fit. then you just need to build it up like 1/16 inch

i did some fiberglass also, but not automotive.

A good set of molds for a popular car are like money in the bank.

worked on the fenders a little more today, i havn't had anytime in over a month to touch them except to transport them to my storage place. today I cut a bunch of fiberglass cloth up and glassed it in to all the points the fender mounts to the car in. It'll act as a reinforcement layer. I think I need to put a second layer on, they still seem a little weak! Hopefully I'll be able to mount them next weekend!!