Talk Composites - The Forum for Advanced Composites

Problem with 2 part mould.

http://www.talkcomposites.com/Topic40034.aspx

By jeffrey bres - 4/7/2021 9:49:20 PM

Hey guys.   Im relatively new to moulding and such.

Now i have a problem.. not sure how exactly to solve


I have a 2 part mould..   made from the easy conposites unimould system..   (all went well up to my last layup.)

Heres whats going on.   Ive made a mould that will be joined after i have layd up both halfs.(rc boat)

Ive made 3 products using hand layup without isseus and had a perfect seemline in all 3 using hand layup...

Now i made 1 vacuum infused.  And my seem was off. On both sides...  the bottom half is 0.4 to 0.5mm wider on each side then the top half..   first i didnt notice.    Trimmed it. Joined it split it and oh sh....   yes.   I thought at first that i had a pre release but apperently not.   I checked the mould.  And yes. Its deformed..(not much)...    is it possible to fix. Or do i need to make a new mould?

(I need 1 more product from it to have a plug to make a new mould. But it would be nice if i had a perfect product..
The plug i used is back to the owner.. and the perfectly straight products are sold... )
By jeffrey bres - 4/10/2021 9:59:05 PM

 
Warren (Staff) - 4/9/2021 8:16:37 AM
I wonder if the heat of curing in combination with being under vacuum has made it move slightly.  You could try clamping it together and doing a proper post cure   -  slow it down compared to the one in the TDS as you haven't got a pattern.

That might help but it also might make it worse! So its a difficult one.

IF the surface is not too detailed, and assuming you had a decent layer of gel, you might be able to sand the lip out but its a fair bit of work.

Ive decided.

Im not gonna take the risk and make a new mould.
I forced it into shape and drilled some new positioning pins in.   So when joining it i will tap these is for now...