Making Flared Fenders My Way

[LeftAngle]

Using the method Chip Foose used on Nivins' Lotus to gain a bit more room for wider tires, worked out pretty well for me.  With the exception of having to deal with the incredibly thin fiberglass, the job went smoothly, the fenders look close to stock and the wheel alignment looks good to my eye.  The result can be seen in the first photo, where the tire and fender are visually aligned.  This looks much better than a tire sticking out from under a fender or a flared fender that looks like it wasn't part of the car's original design.

Of course, this all might change after I pull the car outside and step away to look at it.  And the reason I'm doing one side rather than the other front wheel.  If it all goes south, I won't have to re-do everything, just the side that's completed.

Next, is the right rear fender.  For this one, I made a cardboard mold.  I lined the mold with plastic packing tape and duct taped it over the car's rear quarter.  A gallon of pourable foam and wa-la... A huge mess on the floor and a foam fender on the car... My job skills resume is expanding nicely.

It didn't take long to get to this state.  It still needs a lot of sanding and shaping, but foam is easy to work with. 

I like the transition I'm making from the fender to the air intake.  I'm also mirroring the same characteristic lip that gave me so much trouble at the front.  The wheel and tire will also be aligned with the body in the same way.  I think the worst thing would be if the fender is too far out, making the body stand away from the tire.  I cringe whenever I'm behind an older American car where the body overhangs the wheels by at least 6".

If I do this right, my car won't look like flares have even been added, but like it was designed that way from the beginning.  If not, well, I'll drive it anyway.

Coming up: An incredibly easy way to make a rear diffuser.

[cal44]

Since I am not working on cars for now (doing a house) I certainly enjoy your postings.  Thanks for the pix.

mike

[LeftAngle]

Thanks Mike:  Knowing people are interested in my struggles makes it worth documenting.  My biggest concern is making sure both sides are the same.  The first issue I came across was the material I used to fill the holes that inevitably show up when using foam.  I picked up an aerosol can of foam insulation and it worked very well to fill the place I sanded too much and the holes that showed up in the original foam.  The problem is, the can foam is an entirely different type of foam, more dense and resilient.  This caused the surfoam and sandpaper to produce uneven results.  I pulled the majority of the can foam out.  I'll deal with the holes when I start fiberglassing.

Attached is the way it looks at 9:00 in the morning:  Maybe I'll take a nap... Nah, I don't like the back... Back to work.

[EuropaTC]

Keep posting the pics !  I've got to say it's not something I'd do on my car simply because I don't plan using wheels as wide as yours, but I do like the engineering side of things. And once upon a time I was into the custom car craze over here, so bodywork mods are also high on my interest scale even if I'm not about to do the same....

Brian

ps - is the plan to lay up 2-3 layers of matting on the foam, get a good surface and then take a mold off that ?

[LeftAngle]

That WAS the plan, but because I have no intent on selling them or no where to store them.  I think I'm going to:

1. grind the body at the form line
2. sand the foam to meet
3. cloth
4: 2-3 layers of mat
5: sand, finish and pull the new fender away
6: cut the body away
7: attach the new fender

Having never done this before and not being able to find anyone else who's done it on the internets, I'm into unexplored (for me) territory.

The scariest part is making sure the new fender fits the place I just cut away.  I'll have to build up the difference in the supports behind, but I'm hoping my metal source will also have an old fiberglass shower stall or two I can cut up and use.

My engineering days are behind me and I'm revolting from the retentive task of research and thought-through design that were necessary for production.  It made things not fun.  Now, I'm more prone to a "cut the hole and figure out how to fill it on the fly" engineering style, making things interesting.  Since this is a one-off product, cutting corners improves the speed of development tremendously.  I only know what I want it to look like.

I also have a tendency to take breaks and do other things.  Since my plan includes a diffuser, it'll need to match it up with the fender, so that will probably be next.  I have the aluminum marked out, so if I can find a place to work, I'll do that next, before finishing the fender.

 

[EuropaTC]

I can't see why your plan shouldn't work fine, I guess the idea of making molds is only for if you want to repeat the exercise, sell on parts or plan on having some accident damage 

You mention using an old shower tray.  I also make up flat sections with 2 layers of matting on polythene sheet, this comes away easily and is thin enough to flex into shallow 2D curves, bridging gaps, etc. And things like rubber tubing which you laminate over and then pull out the rubber after curing, this makes a good stiffener on a large flat panel or for a wheel arch radius return ?

But I also do the "dive in and and sort out the mess later on" approach.....     

[LeftAngle]

Glad to hear I'm not the only one.  Had dinner with another engineer tonight and he wasn't as convinced as me that a "proper" job can be done on the fly.  I had to remind him, I'm not as young as he, and for me, time (saved) is worth more than money. 

I'll be working on the front and rear deck lids in the next couple of days.  Since the fiberglass will all be set up, I think I'll try your poly sheet method to make panels.  I've made woving and mat panels before, but used wax paper, stapled to ply as the release.  I doubt my source will be getting an old shower stall by the time I'm ready and if I make them myself I can form them while they're still curing.  I also need to close off and make a fuel gauge transmitter access door behind the driver's seat and the passenger's seat belt anchor under the door needs to be re-built...

You're right... The panels I need won't be seen and don't need gelcoat.  Thanks for pointing that out to me.

[LeftAngle]

Rough... Very rough:

The mistake I made here was covering the foam with blue painter's tape.  The intent was to fiberglass the fender, finish it and remove it.  After it's removed, add a couple more layers of mat to the inside, cut the body away and before installing it, use it as a guide for the left side.

The trouble is, no tape seems to stick to the foam, so the fiberglass ended up with several ripples in it that had to be cut away (those dark spots).

Another tangent I took was to eliminate the flare at the edge of the wheel opening.  Trying to maintain it while holding the fender shape was an experience I don't want to re-live.  Instead, once the fender is complete, I'll feather a flare onto it   as I did on the front.  Much easier.

It'll take a few days to sand the fender to shape and the weather isn't scheduled to let me do the work outside.  Maybe I'll work on the diffuser.

[EuropaTC]

I have no idea if it will work or not, but when you're doing the next one, how about skimming the foam profile with something like plaster of paris or the stuff you use for plastering walls ? It should stick to foam, is very easy to sand into shape and should give a half decent inner surface to build up on later.

Brian

[LeftAngle]

Hi Brian:

I actually tried that, using drywall joint compound.  It held to the foam, but had to be sanded.  It was difficult to see where the plaster ended and the foam started so I messed up the foam in several places and I had to start over.  If I were making a negative mold, I'd definitely use plaster, waxed for mold release.  Because this is all new to me, I'm learning from my mistakes, by I don't know if I'm heading in the right direction.

I've pulled the fender off and am building up the interior. I would like it to be substantial enough to  resist idiots using it as a place to sit.

I'm contemplating finishing them as best as I can and then taking the car to a body repair shop.  That way, I'll have the shape I want, but a professional finish.