Imperfect mould surface.

Talk Composites - The Forum for Advanced Composites

Back

Imperfect mould surface.

Author	Message
Tollaus	Tollaus posted 13 Years Ago HOT Topic Details
Group: Forum Members Posts: 10, Visits: 21	Hi guys! I've made the mould for my second piece of the project and its surface came out with a lot of imperfections. I have sanded it but I took off some black gel coat in some parts, so now the polyester resin from the mould is showing up in some spots and the surface isn't decently even yet. I knew the plug wasn't perfect but the mould came out worse than expected. Here are my questions: 1) can I continue to sand until I get a decently even surface, even though the yellow resin is visible? 2) do I need to re apply the gel coat and then sand it again? 3) I need to to even out the surface with bodywork filler and then apply the gel coat again? I do not want to make the mould again, so which is the best way to do it in your opinion? Many many thanks in advance!
	Reply Like 3
Reply
wozza	wozza posted 13 Years Ago HOT Post Details
Group: Forum Members Posts: 688, Visits: 5.4K	I have found myself in similar situations in the past, so this how I would deal with the problem for what its worth and the questions you need to ask yourself. 1- Is it a large/high value (in materials terms) part and can you afford to risk producing a sub-standard part. 2- Is the mould going to be used for a "one off" or multiple runs. 3- How bad are the defects in the mould. 4- Is the part for decorative or functional use. Once you have answered those questions its easier to decide how to proceed. If its a "one off" then your time may be better spent correcting the part rather than the mould. If its for multiple runs then spend the time getting the mould right. It is very satisfying releasing a part from a mould that only requires a trim and a quick polish. If it is a functional part as long as the imperfections don't affect the structural properties then does the surface finish really matter? I have repaired/altered moulds by reapplying gel coat many times with varying degrees of success. If the imperfections are small, pin holes etc be sure to make sure that you remove all traces of sanding dust grease etc otherwise the gel coat may not bond properly to the previous coat and you will be left with bits of gel coat stuck to the surface of the part. Resulting in more time wasted finishing the part.(I have learnt the hard way) I have even made the imperfection bigger with a stanley knife to increase the surface area to achieve a reliable repair. If the imperfections are relatively minor then gel coat and sand back. If another layer of gel coat is not sufficient then I would be looking at reworking the plug and a fresh mould. Sorry if this sounds like a long answer to a simple question and good luck Carbon Copies Ltd
	Reply Like 3

Merge into selected topic...

Merge into merge target...

Merge into a specific topic ID...

Threaded View

Imperfect mould surface.

Tollaus - 13 Years Ago

I have found myself in similar situations in the past, so this how I would deal with the problem for...

wozza - 13 Years Ago

Hi Wozza, Thank you very much for your answer. The mould is used to produce several prototypes, so...

Tollaus - 13 Years Ago

The standard usage of unimould or most tooling gelcoats normally leads to a thickness of about 1mm....

Warren - 13 Years Ago

Thank You very much to you both for your suggestions! I'll let you know about the result. Cheers.

Tollaus - 13 Years Ago

Hi Tollaus, These types of problems can be very frustrating and I know how tempting it can...

wozza - 13 Years Ago

Is it OK to bump this over to general composites as I don't think it relates directly to any of our...

Matt (Staff) - 13 Years Ago

Reading This Topic

Login
Remember Me Reset Password Resend Validation Email Login	Facebook Google

Imperfect mould surface.

Imperfect mould surface.

Merge Selected

Threaded View

Similar Topics

Reading This Topic

Login

Explore

Messages

Mentions

Search