New Mold-Need Help

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#1

Hello Good People,
I have a new mold and plug. I will use for making model racing yacht hulls.
The mold is two-piece as you can see. The line for the two halves is supposed to precisely follow the keel line of the hull. Well, it isnt quite perfect. This I can live with as the dimensional integrity of the hull is still very good. What I cannot live with is the amount of gap at the join line. I knew there would be some flash with the epoxy resin at this point, but the actual gap is larger than I expected. I cannot take the time to rework the finished hull after I pull from the mold. I mean if it was a minor amount of flash it would be ok, but it seems it will be alot more than minor.
I will be using Resin Infusion Process and a post cure heat treatment of 70 to 75 C.
This situation has to be somewhat common. What can I use to fill the gap between the mold halves?
I would prefer to work the mold to get a smooth surface down there. I will not necessarily need to take the mold apart to release the part. Its a simple shape with no undercuts as you can see.
Its a new/green mold that has only been heat cured. There are no surface treatments/chemicals on it at this time.

Any help will be appreciated, Thank You.

#2

Using clay or wax in the parting line will help minimize the flashing.

#3

Ok, so it was suggested that I use body filler as someone else has done on a four-piece mold that they use. I am thinking that it might be prudent to fill the flange where the halves will meet with body filler then re-clamp them together. I can then eliminate most any void in the surface join and clean up the overflow on the mold surface, leaving a faired and smooth surface.

Temps for the post cure will only be between 70 and 75 C. Most any good synthetic body filler should withstand those temps.

Opinions?

#4

Clay. Easy to clean. Or try parting paste. What release system will you use?

#5

Most body fillers will shrink quite substantially at anything over 60 degrees, which is why decent spray painters and panel beaters dont like using them. I wouldnt recommend using body filler on any mould, let alone one that will be subject to elevated temperatures.

To be honest, I actually think that is quite a nice parting line. Its crisp and sharp, with no chips out of it. It should only be a 5 minute job to clean up the flashing on the finished part.