Painting and Fiberglass Mold Prep service wanted

[Roux]

I am looking to farm out some of my mold preparation work. Two piece engine cowl mold for my FF that I am laying up and fairing in right now. I come here first in case people on our community need the work. My second choice will be to engage the local auto body shops who likely have a lot less work this winter since commuter traffic is down and fewer cars are plowing into snow banks like the old days. Steps:

1. Prime the mold cavities with 2 part epoxy primer (or some suitably hard surplus paint?)
2. Wet sand 400/600/800
3. Polish to shine
4. Apply 8 – 10 coats of parting wax
5. Apply 3 coats of PVA

I am interested even if someone only wants to do step 1. I have difficulty spraying smelly paint without marital stress. All the rest I could bring back ‘in house’

PM me if you are interested in quoting the job and are within 2hours drive from 06812 area code. Shipping makes no sense due to the size.

Thanks

Steve

[billtebbutt]

A local community college is prepping and painting all the bodywork for my RF90. They have a full-on autobody tech course there, and the prof and students were pretty keen to take on a fun and interesting project. They will only accept payment for materials, but i will try to make a donation on top of that to the program. Either way I come out of this way ahead vs a commercial body shop that gouges on price and does crap work (has been my recent experience).

You might try seeking this option out where you live?

cheers,
BT

(PS. They charge a total of C$800 to fully prep and paint the average street car, my job will be considerably less than that)

[EACIII]

Back in the day I would tell you to call Steve Maxwell - but he is out of that business now. Not sure what he is up to.

One advantage of the detached garage. But too cold there in the winter to do that type of work. So I hold off till spring. Open flame heater and flamable chemicals not a good combo

Ed

[Ed Womer]

Why would you want to spray epoxy paint on the mold surface? Have you heard of gel coat? Two layers of gel coat will let you do the required sanding to get a good surface without sanding through to any mat/cloth. Also unless you are making a lot of parts you don't need to do all of that prep work of waxing and release agent PVA and just spray or brush the PVA on the mold.

I have molds for cooling ducts that I never sanded or waxed and just brush on PVA and have made well over ten parts with no problem.

A couple of tips for the casual part maker, make your own gel coat by adding Cabosal, don't know if that is spelled correct, to the resin to thicken it up so it won't run, that is how gel coat is made. When mixing the resin with hardener or what ever use a drill with a mixing apparatus since it works far better than a wooden stick and just have a container of acetone to stick it in after mixing an run it to clean the resin of of the mixing apparatus so you can re use it over and over. I use a plastic soda bottle cut off half way. Also I use the bottom half of a two quart milk container to mix the resin in and pour it out of a corner onto the surface.

Most important find an old furnace fan and mount it in a wooden etc. box that you can add filters to each side and make so you can change the filter when it gets clogged. Furnace fans almost always have three speeds and wire each speed wire to a switch so you can run it easily on any of the speeds. Then adapt a way to exhaust out of a door and open a window on the other side of the room so you get a cross flow to remover any odor or spray. Also put plastic on the work table and floor to keep and drips etc. from making a permanent mess. When I started doing this I could make fiberglass in my attached garage and after done you couldn't smell the resin in the house. let the fan run on low after you are done until the part hardens.

I still have this same system and it is now in it;s third location. As long as you have a fresh air source and an exhaust location that are on different sides of your work space it will work fine. I run the fan on high when I spray anything and on low when laying up. I don;t even use a mask when laying up since if you have good cross flow it should remove all fumes from your work area.

Ed

[Roux]

Ed,

thanks for the helpful input. I recognize many of your suggestions. I chose to call out epoxy instead of gelcoat since the mold is made with epoxy and adhesion will be better epoxy to epoxy. The molds are nearly done but will need some minor surface cleanup on the inside, hence a coat of paint or gelcoat as you suggest would work well to allow for sanding out the final little scratches, bumps and hollows. I have tried the fan. It is built into the wall with a nice box where a basement window used to be. Even had a variable speed controller at one time. I guess I am dealing with a person with an above average sense of smell on that front. I did spray PVA onto the plug when I made the mold. No issue for me to do that again but this time inside the mold. I do think something better than water based paint for the mold surface is the way to go and since I would be buying material for that coating I thought buying an epoxy primer might be better for that sanding layer. The epoxy resin I am using is not offensive so I could mix cabosil into epoxy resin and brush it on and just have a bit more sanding to do. In summary, I am not stuck without options. I was just looking for some opportunity to speed up what I am doing and perhaps support a racer or race shop that needs a bit of work.

regards,

Steve

[Ed Womer]

I didn't realize you already had the layup for the mold already done. When starting to make the mold over the model/part to make I have found that two coats/layers of gel coat is best before adding the cloth or mat. If doing two coats you should let the resin set up but not totally hard before adding any additional layers. I test it by touching the layer or what remains in the mixing dispensing cup to see if it will not stick to your finger but will leave a finger print on the surface.

Yes I wouldn't use any water based paint since PVA is a water based product that you remove with water from the mold and part. Also there are different waxes used if you want to use PVA over the wax verses just laying up the part on an already good wax base that will allow the part to come out without needing the additional PVA as barrier. My molds for the vee parts have a pretty good finish and I only put two coats of wax on before making the part and they release fine. I also don't use color when making a mold and when you make the part use color and you can actually see it release thorough the clear mold.

You might want to just use two coats of PVA and make a test part to see what your surface finish looks like and keep in mind it is a race car part and will ultimately be damaged so no need to make a show quality part.

Good luck, Ed