COE Mold for Fiberglass part??

Any of you guys done a mold to build a fibergl*** part? I'm thinking about making 2" wide "fender extensions" using a plaster of paris mold. I've never done anything like this before.. How do you keep the p-o-p from doing any damage to the original FG fender? Is there some release agent? Same questions on the new form, seal it? Release agent? And what about laying the thing up? Layer of resin, then FG matt, then more resin?

 

Contact someone like West Fibergl*** systems (https://www.westsystem.com/) and see if they have a release agent. Many moons ago I was an aircraft fibergl*** tech; we used a liquid wax we sprayed/wiped on molds. Experiment with spray car waxes?

On my own projects since I simply cover item that is my mold with Saran wrap! Works! Be sure to masking tape adjacent areas; the resin gets into all sorts of surprising places as you panic to finish before cure! Chuckle.

But my projects have all been smaller than an entire fender. This much simplified, read between the lines: My method of making a mold is to layer fibergl*** over my subject; let cure; attach wood and or foam boards as frame per application and fibergl*** with strips and resin caulking described next to the now cured mold; remove with care; trim edges; sand as needed. You might want to apply/spray a gel coat on if the experts (West) recommend a suitable release agent, but I would approach this myself by gradually laying my first cloth over the original now protected fender and brushing the resin on; keeping numerous plastic applicators of various sizes and brushes ready to hand to squeeze/squeegee excess resins and air bubbles out. Generally I use foam brushes as well as hair brushes. You will want a few pairs of gloves at hand, lots of wipes, and a good buddy to ***ist! Perhaps somebody to help with timely mixing of extra resins and then cleaning your plastic applicators and handing you new brushes.

There will always be air pockets and imperfections. These can be filled with a fibergl*** resin/paste/caulking you can inject into or spread onto such areas. Use veterinary needles for injection. You van buy a variety of fibergl*** micro "bubbles" to mix into the resin (or be creative... I often simply use cedar wood dust and have even used linoleum filings [battle ship tiles] as my thickner. you want enough thickener to make it pasty, but allow it to flow a tad too. Once cured then sand and smooth as required. Depending upon your final finishing goals you may want to spray this mold with a gel coat after applying a release agent (wax) for the actual part layup. But you may simply want to make a rougher item and finish per routine autobody practices. My personal projects are basically repair and or kayaks, not a show quality custom. Refer to You Tube as well. and fill in my gaps.

BUT... it is fairly simple work. And fun, satisfying. I heartily recommend you experiment a bit with a smaller item, learning how to squeeze out the excess resin as you apply layers of fibergl***. Too many folk leave too much in place leading to excess weight, reduced flexibility, and a more brittle end product.

West products are fantastic from my experience! I also regularly use POR 15 seam sealer and two part epoxy to produce my final results. The results look very good and last even on my 4x4's!!!

You will obviously want to consult with autobody paint finish suppliers for recommended primers. And clean things up very well with acetone before any finish painting. The acetone removes final traces of release wax.

Consult MSDS and use masks and gloves as recommended; some POR15 items (example epoxy) non-toxic and wonderful to work with bare fingered as you can smooth into place by fine touch! Love it!

BTW: It stinks up the house pretty bad if your garage is attached. Just a warning. But heh... I have done projects in my living room when I needed the space. Chuckle

I haven't reviewed what I am writing... dinner time preps now... so ask if I have been confusing...

 

I use PVA wood glue as a release agent.

Spray it on, let it set and it stops the resin sticking to the surface.

We once sprayed a Porsche with PVA then painted a green car white for an advert.

When the filming was finished we used a pressure cleaner to blast the white paint of together with the PVA glue, that melted with the water.

 

Great info, guys!!! Thanks very much... I particularly like the message that its fairly simple and satisfying. You see what I've built so far as a rank amateur, so surely I'm up for a small challenge.

Just to clarify, I am not trying to reproduce an entire fender. I want to build an "extension" for lack of a better name. The FG fenders I have today need to be 2 inches wider. My thought is to reproduce the first 2 inches of the body-side fender surface, the flange that bolts to the body and then an additional flange for bolting to the fender. Essentially it would be a upside down U shaped piece where the sides of the U are flange surfaces and the bottom is the actual fender surface.

I'm a little nervous about putting FG resin near my FG fenders to make a mold. I think I'd opt for something less dangerous like plaster. Longevity of the form is not an issue, it only needs to make 1. Being able to pull the plaster w/o damage to the FG fenders is my main concern.

 

Burlap and drywall mud makes a good temporary mold. Lay it up like FG, but let each layer dry over night. There is some shrinkage, so a few layers of masking tape on your fender before laying up the mold will help you get the size correct. On a piece the size and shape you are talking about, gl***ing (mudding) in an exoskeleton will control warpage.

 

I think I'd make it out of steel. If I understand correctly, you want to space the fender 2" away from the body. So, a flange to the body, then 2" and then another flange to bolt to the fender. Starting at the fender with the flange secured, then scribe the form, cut, scribe another 2" and cut, weld. I know stuff is made from fibergl*** but I'm pretty sure if I tried to 'gl*** them I'd wind up shedding the fenders as I trundled down the road.
If not, can you inbed some strips into the flanges to strengthen them? Do the fenders have something in there or just holes in fibergl***?

 

Studebaker did this exact thing on the41-47 M series trucks. 1/2 and 3/4 ton models had no widening strip, but the larger models had different width strips depending on track width.
What would be wrong with cutting a wood strip to fit the flange, wrapping it with FG to stabilize and accept body and paint work, then bolt through the whole works with long bolts

 

Yeah Wagon, "shedding" the fenders is a concern. It is minimized by the fact that I'm only going 2 inches and plan to lay plenty of FG cloth in there.. But your point is well taken. I do not think the fenders have anything in them, but the company that made them certainly has a solid and long-standing reputation.

I like the idea of shoring up the extensions somehow. Not sure I want to add so much that I can bolt thru them, but maybe just some 16g U shaped "brackets" at several strategic locations where bolt holes will be. I suppose that brings up also being able to seal them after I drill the bolt holes, doesn't it?

Building them from steel is far beyond my talents and available tools.

 

I'm sure you have your reasons for going with an extension, but if it were me, I would seriously consider splitting the fender and adding the 2" up the middle. I've gone this route on steel fenders. (using a steel strip, of course)

 

I have considered that, but I think it's just too far beyond my skills. If I screw up the extensions, I've only wasted time. If I screw up 1000 bucks worth of fenders that'll hurt. I do question if the extensions would be the right contour or not...

 

This is a sound idea fourspeedwagon: I have used strips of metal rain gutter covers, those with the perforations in them, both to provide a base for missing sections during beginning layup and as a way to strengthen such sections. I will be repairing some shattered dually fenders shortly in this manner. The fact that the fibergl*** resin squeezes through those perforations allows an extra grip and you can later apply another ply or plies of fibergl*** strips to that underside side as ribs or coat entirely. I have also used stainless steel mesh to make forms for curved areas; works wonderfully as you can stretch it into/along the pre-existing item. BTW: This also works well with POR 15 products; Google POR 15 if you are unfamiliar with those products. There is a time and a place for these products. New age chemistry at its best!!! I have successfully used to repair rust perforations in steel bumpers and indents in plastic bumper covers. Stands up for years!!!! Blends in seamlessly if painting.

FYI: Fibergl*** as well as POR 15 products end up with results stronger than steel relative to such uses. Just ask Boeing Aircraft... or look outside the window of your 737/747/7?? the next time you fly. Fibergl***, resin saturated honeycomb cores, and aluminum this and that ribs, electrical conductors making up those wings... and the ****ter... etc!!!

You can also embed nuts inside your layups if planning to attach the item such as you might with a flanged fender; clean with acetone prior to layup; skuff em up a tad. Simply stuff the inside of the nut with plasticine prior to lay up and sand down after curing to reopen the threaded hole later. Reinforce these zones once satisfied with fitments with the resin caulking I noted in earlier post. If you don't quite nail things alignment-wise... yup... dremel it out and start that section over. Feather your patch by sanding beveled area around said area and cutting appropriate patches that will overlap. You can purchase different thicknesses of weaves and even strips (like rolls of webbing) of very thin weaves of fibergl*** from West I believe.

 

I REALLY like the perforated material idea. where would a guy find that SS mesh stuff you mentioned?

 

I don't think you really need stainless, it's completely encapsulated. One material that's easy to get is wire lathe, it's in the drywall section of your favorite building center. (But I do think the strength requirements are being way over-thought in this thread)

 

I bought a bunch at a garage sale one time. I think a metal supplier might be able to source same; no doubt more expensive than what I paid. But I have also used other meshes. Steel/aluminum? window screen mesh too. The key to stainless mesh I used was not regarding rust concerns, but that the mesh was a finer gauge and molded readily to the contours of the parts being repaired; I should have stated that more clearly. And this too was as much used as a carrier for the resins, POR 15 products as well as fibergl***, as it was for additional strength. I cannot find the exact locations where I did these repairs on steel front bumper as one example despite years of use and harsh climate effects.

BTW: Today I used the POR 15 two part epoxy to fill some "awkward" gaps in some photo frames I am making for the wife of a senior who has had a stroke. The gent is now in a care home and the photos are of him in his younger days competing in rodeos. The wood is from boards I cut out from their now old unused corrals. The wood is old, co****, somewhat warped and uneven due to livestock chewing on some areas... simply difficult to fabricate the best results as is. So once the POR 15 epoxy I pressed into some gaps is cured overnight I will rasp those areas a touch to mimic the rough finish and mix some craft paints until I get a suitable touch up colour to match the aged adjacent silver gray wood. Once I started encountering problems I relaxed and told myself, "No problem; I'll polish them off as needed with POR 15 epoxy." I have used this product to repair damaged base boards, window frames, furniture, automobile parts of all sorts, pottery, jewelery... it is easily molded into the space needed, sanded, filed, drilled, tapped, and holds a great hard sharp edge. And I have used a variety of finishes on it to affect virtually undetectable repairs. fabulous for repairing cracked steering wheels and other Bakelite material parts. Press it into/onto your one good emblem and you have duplicate or mold!

(POR 15 should be paying me... I think I have sold all sorts of this stuff and their other products for them over the years demoing it to acquaintances and relatives. --- Chuckle)

 

Loose plan coming together based on everyone's input... here's what I'm thinking..

Use drywall mud on test piece of leftover FG Corvette body. It's a lower section of a front fender and has a flange similar to the COE's fender. Test mold will be about 12"x6".
Cover FG test piece with a couple layers of Blue painter's tape to allow for mold shrinkage and protect the FG piece.
Mud Corvette piece, embed something in the mud for strength. Burlap, perforated gutter covers, screen.... ??
Build in layers to desired thickness. Not sure how thick...??
Coat completed and cured mold with PVA wood glue, although I wonder how GLUE can Release?
Layer in FG resin, cloth and something for strength... Alum screen maybe?

That's it so far...

 

BTW: There is a 47 Ford one ton pickup model that has such extensions for the wider wheelbase available back then. I wasn't aware of this until seeing one the other day. Learn something new every day if you pay attention I suppose.

 

Wheelbase is the distance from the centre of the front axle to the centre of the rear axle. I think you are talking about track width. Without my testosterone levels coming into play why can't you take some pictures of these things you write about as well as your projects SpagScot ? I just think if your going to enlighten us with your opinions and expertise you could share some pictures as most here enjoy seeing what each other is doing, just saying . If anybody thinks I'm out of line just say so and I'll leave this group.

 

Don't know about Fords, but here is the Stude style That I wrote about earlier.

 

Yup... you are 100% correct and that was my intent to type same; I understood that and am humbly corrected as to "track width"; my bad; "brain fart" as they say. Happens. Life.

Regarding photos and projects. I suppose that my lack of photos is because I have never thought my projects that I have mentioned regarding the fibergl*** items as worthy of such effort. But yes, the next time I tackle a fibergl*** repair, or even a POR15 ***isted project I will do***ent the steps I take and post. My experience and technique may just help someone out. Heck, just used some POR15 epoxy the other day to mimic some wood on some photo frames, but never thought anybody would be at all interested in same.

I think have pretty much posted/explained before... my C.O.E. project is merely in the stages of me gathering the "smalls" I want for my build while I am literally frozen regarding what route to take as to the finished project... "Am I sticking with stock ch***is and mods to that or am I dropping cab on a more modern one?" "What wheelbase should I run with?" and regarding that... just last week I checked out a P30 van for sale (another HAMBer's recent advice for me inspired same trip) and a day or two later I drove to the shop and met and discussed my quandary with a fabricator I learned about only the night before. Well in truth I heard about him a few times before, but only learned of his exact location that eve. I do not have the shop space nor enough of the equipment to pull off my hopes and dreams within my budget... and as I see it... why buy all that equipment if I am not going to keep it ?... especially as, like you I will be downsizing/moving in a few years, so YUP... I am going to farm out some of this work to someone with the skills to make it safe first, and next, as close to "perfect" as possible. I simply do not have the experience with decisions such as "stance" as an example. And I am in total awe of this dude's work and it was as if he could read my mind... answered questions before I could ask!!! SO... until I make that decision and make those first "cuts" ... why bother posting Dawg???!!!

Some truly wise dudes I have had the good fortune to meet have shared this Golden Rule as I call it: "Develop a Plan". So I am listening.

Currently degreasing underside of wife's Jeepster project. It is in a very confined workspace, but I am not picky... simply happy to be at it! But I have to squeeze myself between things to get under to do that... so... yeah... never once dreamed of snapping photos. 'Sides... do you honestly want photos of greasy rags?

Meanwhile... had a colonoscopy earlier this week too. They sent me home with pictures. Do you want me to post those?

 

"Patience Gr***hopper". I am having to have it. When I bought it I was hoping to be driving this thing by next year (bought the C.O.E. in 2015), but once I learned more, and more, and more... truly learned what I had bitten off... so now... patience.

 

I knew the Stude's did that on the rear, stepside fenders, but I did not realize they did the fronts too. Thanks fo posting that.

Spag, feel free to post up any ****ty pictures you take... BWAAAHHH!!!!!!!!

 

Did you know that the front and rear fenders are the exact same part? Studebaker, being an independent, had to cut corners to stay with the Big 3 and they were quite innovative at times.

 

They are photos of my exhaust system after all?

Seriously though, I am not sure when I will tackle the dually fenders, but when I do the process I have mapped out already in my mind it may be of interest to someone less experienced with working with fibergl***. My idea is experimental even for myself, but I am certain it will be a good way to go with this specific repair. And perhaps I can take clear enough photos of such things as squeegeeing resin down to a decent saturation to maintain strength but reduce weight and reduce chances that end product will be overly brittle. This can easily be overlooked by a novice. So... yes... if I can help... well it will be my way of thanking/paying it fwd to those who have shared photos that have been educating me how to proceed with my own C.O.E. goals.

Meanwhile I need to drain a fuel tank, install a new fuel pump, filter, on another vehicle I am planning to sell to fuel the C.O.E project expenses and also wanting/needing to replace rain gutters and side markers on my daily driver's service box, before I intend to tackle dually fenders. LIFE

 

I read that recently- do you recall what model(s) they did that on? Pretty clever.

 

Just the M series 1941-48.

 

Having a beotch of a time trying to get the drywall mud to dry... Per the wife, moved from garage to ba*****t... Not holding out much hope. I think it will need to be in a dry place with the heat cranked. This is only the first coat on the Corvette test piece. At this rate, I won't have anything done for the COE until 2019.

 

Idea: I have thought about trying this for a motorcycle fairing I want to modify for my wife's bike...
If you have a hard object you wish to use as a female form for your mold, duct tape a heavy duty plastic bag to that item well enough to withstand the expansion, then spray insulation/construction foam inside the bag... just enough obviously and using the nozzle with the spray bomb to reach out to furthest corner and then backing out...

Once that form hardens apply, trim the bag as best as possible and use plaster or fibergl*** or POR 15 "resins"/seam sealer to finesse the surface, to fill in gaps, air bubbles... sand accordingly...

An experiment, but I suspect a worthwhile one.

 

Interesting idea... I guess the question becomes applying a surface to the foam good enough for a mold. As you mentioned "plaster, FG or POR".

I moved my test piece above our furnace. That will either dry it or fry it.

 

I think it will dry here...

 

It dried just fine.. Of course, hanging 2 fenders above the furnace might be an issue. I might have to wait for spring or go visit Blue!

Hardware Cloth installed and another coat added.

I need to devise a way to get a second flange on the test piece and the final product. I'm thinking that once I remove the mold from the piece, I can cut back the mudd enough to expose hardware cloth the same depth/width as the flange. Then, bend the hardware cloth at a right angle to form the second flange and mudd it. The surface doesn't have to be perfect and I can sand it, of course....