i know this has been covered a few times but i still find this the biggest problem of the entire mold making process 
previously ive filled the gap with plasticine(kids modeling clay) but it takes forever and is a pain.
i seem to remember reading somewhere that someone used a tube of silicone bathroom sealant to fill the gap,this would be very quick and easy for the gaps i have to fill but will it work or cause problems???
I use clay like you, what tape are you using for your flanges?
also have you though about make that into one mold and do the pair at the same time? My door panel inserts are one mold, saves manufacturing time and also save materials
this is a two part mold,the bottom edge is the parting flange.im using aluminium tape,its great stuff,no need for any release agent 
Just keep using clay. It doesn’t take long after you get used to it. What I do is roll it into a long worm and lightly lay it on the flange. After you got it all the way around the piece start lightly pressing it in. Then drag your finger over it. follow that up with the edge of a popsickle stick and you’re done.
i asssume all this aluminum tape business is for using PER? I just use packing tape for parting flanges, but i’m using Epoxy.
epoxy for molds?
the short answer yes
the long answer, yes and we have 10 year old molds. we have 2 years old molds with over 500 turns on them. so if there’s a problem with epoxy molds, you would have a hard time convincing me based on my observations.
this isn’t the first time someone’s got the cocked dog face look and said what? is there a golden rule that’s being broken or what? when i got to this company that was the thing we were doing. and still doing it.
nothing wrong with it,its just the expense aspect i was wondering but i suppose they pay for themselves if they last
Epoxy molds don’t shrink, so dimensions are stable and the EXACT dimensions of the plug, for the life of the mold. PER/VER molds shrink, sometimes so much the mold designer has to take this into account to insure a properly dimensioned final part.
Epoxy molds don’t stink.
Mold life is usually far greater with epoxy based molds.
Epoxy molds are usually stronger than a comparable PER/VER mold of the same fibers. You can make a virtually indestructible surface with high strength/high temp tooling resins.
BUT epoxy molds cost more as an initial investment.
but epoxy doesnt work with CSM does it,or did i read you can get a special type…
that is right it will not work, I use epoxy clay and I get that epoxy on ebay that is like $225 for 5 gallons and use that when making epoxy molds, I make them when yes the part has to be precise! Mostly smaller parts
well i found an easier way…i got my wife to clay them up whilst i was at work today :lol:
cheers to that
my wife works in a boat factory she actualy was the one who taught me when i got started and she helps me through crunch time
You are right about epoxy molds lasting longer. and they don’t shrink to as great a degree as per/ver, I use them all the time if I want a mold that will last.
I also use epoxy tooling foam (paste/clay) it comes in two parts and can be mixed like bread dough (kneaded) I get my wife to do that, just kidding. It can be rolled out like pie dough into 1/2 inch thick sections and placed on the laminate. Then you can lay glass over it. It makes a very very sturdy mold and is comparable to using balsa core or foam core in the tool.
I also found syntactic foam that can be mixed with mekp and pressed on like the dough. then you can lay glass over it and it makes mold build up so much quicker.
where are you getting your epoxy clay and how much?
I am buying my epoxy clay (tooling foam) from Michigan fiberglass. It is their brand. I will have to look it up can’t remeber exactly what I am paying. I also buy a different brand from him for a little more money, but it kneads quicker and is a little more expensive. it is from Ad-Tech In charlotte Michigan. They are owned by another company now
http://casspolymers.com/
The tooling foam we buy from them is great. I also get my syn foam from Michigan Fiberglass for use with pe and ve.
if you call Michigan fiberglass, talk to Chris Blicharz and tell him Doug Sent you.
i said one other time, you’d have a hard time convincing me it doesn’t work together. 10 years old and zero repairs. there’s something there. we use a normal csm that you could find in your local neighborhood tienda. i found though with the R/H we use that the resin isn’t there to wet the glass out so much as the glass is there to keep the resin from falling off. sure there’s the obvious glass reenforcement that’s happening but a 1/4" thick chunk of our resin is not easily broken by hand. although i’m not suggesting that i’d ever make a mold just from the resin, i’m simply explaining the resin.
so if it doesn’t work. come down here and prove it to me, cause i’m just not seeing it.
what type of applications are you refering to when you say that epoxy and mat don’t work together.?
Jeremy, I was always told not to use it. I am not going to argue with results, but I am going to give it a try myself.
How is everything going with the job?