Noob Questions

General Composites Discussions Composites Talk
#21

Next time, wax your original/mold well (5 apply and buff cycles) and stay away from PVA.

#22

I made my first part with no PVA. It released easy. I still use PVA on my plugs, but it really is all in how you apply it and since you have some PVA there… use a slightly damp CLEAN lint free rag to apply the liquid PVA to the plug. or spray it on in very very thin coats using a spray gun. If you do the spray gun route do about 6-10 coats. I know TET hates PVA but eh you bought it and you have it there, might as well use it. Also keep your PVA and other chemicals out of sunlight and in a cool place to make them have a longer shelf life. A refridgerator is not needed but if you have a spare one just for chemicals it’s useful.

Also you can attach the metal flange to the bonnet with aluminum foil tape, also available at a hardware store. Don’t worry about resin sticking to aluminum foil tape…it won’t.

Clay, you can use modeling clay to fill in the tiny gap between the flange and the bonnet. Take your time and make the clay perfect.

Also if using polyester or vinylester resin for mold making, only do two layers of CSM or the heat will cause problems when the resin exotherms. I used to wait one hour before adding more resin and CSM or fiberglass cloth. Also let your polyester gel coat get past B stage but not completely cured before you start applying resin and fiberglass.

I highly suggest for any new person to composites to read up on polyester resin and gel coat mold making. You want about a 15 mil thickness on your gel coat, less and it will alligator, more and something else bad happens.

You are definately at the right forum for this stuff :cool: Lots of folks here to help with any problems or questions you may have.

#23

I have no Acetone, but have some of the missus nail varnish remover which has acetone in, could i use that?

Hot water i have plenty of, would i just pour it between the mold & plug?

No heat gun either, shall i use a hair dryer?

Thanks john

p.s i shall get pics up soon, camera now charged!!:cool:

#24

quick update for you, i have got the mold off, and your right, no good but i will keep for a learning point.

Feel really positive about doing another as the finish is really smooth and even.

The edges wouldnt be any good for a mold so i will use the tape and cardboard method i think for next time.

Anyway gonna shoot some pics and upload to photobucket then whack them up here.

Let your eyes be the judge!!

Thanks John

#25




#26

Learn from your experiences and don’t repeat the bad ones! :wink:

#27

well said that man!

I dont intend on making same mistakes again!

Whats the easiest way to get bond something to the side of the boot to allow the fibreglass over the edge to make a good mold?

Some say cardboard some say sheet metal, i just want something cheap and easy to use! p.s can get cardboard free so unless its a real pain it the ass ill use that

Thanks John

#28

The bold red section above is that meant to say 15mm or 0.15mm?

Thanks John

#29

Neither, although a 15mm gelcoat would make one heavy mother of a mold or bootlid!
Remember these guys in the US don’t do metric. I would say aim for about 1mm thick, although when you are brushing it on it’s difficult to tell. Just one thick coat will do, if it runs when vertical it’s getting a bit too thick, I’ve never had any problems with putting on too much, I even used to put on two coats in some very detailed parts, but everyone experiences are different.

The answers to your other questions are all in this thread. Double sided tape can be had from double glazing or UPVC (soffits, fascias) suppliers in the UK. Aluminium foil tape (for covering cardboard) is used by pipe laggers and air-con people.

Are you racing this car on Sunday?

#30

no, unfortunatley i am not ready in time for the season this year, i will be entering next year once car is to a satisfactory level!

Thanks John

#31

Ah, so not such rush then.

#32

is a flow coat the same as a gel coat?

can i use a flow coat first then use as said above for gel coat “leave til tacky” then add polyester resin and tissue material?

If not how do you use flow coat?

Thanks John

#33

also what is the best way for me to apply this gel/flow coat?

Do i need to spray it with big panel like this?

Thanks John

#34

Hey John I recognize you from Driftworks :slight_smile:

Hows the project coming along?

If your still looking for UK suppliers try here They seem to have everything needed to do most projects:)

I ve taken the expensive route and booked myself on a basic composites course with carbonology.com, just so I can get a little bit of direction before I start doing my own projects.