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jeffrey bres - 9/20/2020 7:28:06 AM

hi all.

i recently made my first rc boat mould using the unimould system.   i used pva for the bottom part of the plug. and easylease and pva for the top half.

these came out fairly well. but not as smooth finich as i hoped.   so hours of wetsanding and buffing later..

i put on 7 layers of easy lease.  eg60 transparent gelcoat 2 layers as even as i could with brush.  2x 200 glass 1 carbon (240 or zo i believ) and another 2x 200 glass. for the deck half.    in the sharp corners i made a fillit of epoxy and thixotr...between the gelcoat and the glass to have the sharp corners evened out.   so far so good.   al went in super smooth.  

30 hours later.   i wanted to pull the part.....

i allmost thought i would break my mould.   the edges with the fillit where so stuck!. 

now i think i put the release agent on and buffed to hard.

heres question 1.    i cleaned the mould. put the easy lease on thicker.   didnt buff at all.       and i read i can wax it.     now before i want anything on top of the easy lease.   what do i do when i pull it.   do i need to clean it completely and stard over with the easylease. or can i just remove the wax and doe 1 or 2 new coats of easy on it.

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Rosta Spicl - 9/21/2020 12:46:34 PM

The chemical release agents are the top quality what you can use. There is no need apply others like a PVA or waxes. I'd like recommend don't use anything other if the chemical release agent has been already applied. From my point of view the best to sand and polish all the mould to be sure, all the layers of release agents you used are gone.
It seems the mould is black epoxy gelcoated, OK, but the surface has a microscopical porosity, that's the reason to use filler (for example Frekote FMS) for first 2-3 layers before release agent. The 5-6 coats of easylease are obviously enought.
Are you absolutely sure, there are no negative draft locks on the mould? Especially around the inner rounded corners.

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jeffrey bres - 9/21/2020 3:32:19 PM

+x

 

Rosta Spicl - 9/21/2020 12:46:34 PM

The chemical release agents are the top quality what you can use. There is no need apply others like a PVA or waxes. I'd like recommend don't use anything other if the chemical release agent has been already applied. From my point of view the best to sand and polish all the mould to be sure, all the layers of release agents you used are gone.
It seems the mould is black epoxy gelcoated, OK, but the surface has a microscopical porosity, that's the reason to use filler (for example Frekote FMS) for first 2-3 layers before release agent. The 5-6 coats of easylease are obviously enought.
Are you absolutely sure, there are no negative draft locks on the mould? Especially around the inner rounded corners.

i did polish and buff the mould again.   8 coats easy on it. 3 waxes. and the part allmost fell out out of its own after 24h.

the bottom half has more isseus.  still working on getting it smooth..
any tips on keeping these air pochets out? on the inner lip?    

i will make a new mould in a few weeks.   il do as you suggest. no more wax.    and more shiny mould.