Marshall Tucker
Member
This is my first question and I hope it's not a stupid one but as I've noticed one of the Preferred methods of casting polyester resin is to thin it by heating it. What are the pros and cons of thinning it with styrene by 10%?
Thinnig resin
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its_virgil
Member
Hi Marshall,
Thinning PR helps with the removal of air bubbles. Using a water bath seems to be the easiest way without purchasing more stuff. I'm not real sure heating is the preferred method (preferred as in being used by most of those who cast PR). It would be interesting to see how many casters actually heat polyester resin but I will not be setting up a poll.
I can't comment on thinning with styrene because I do not use styrene to thin. I'm not sure what the final effects on the blanks would be using PR thinned with styrene. I will not be trying it but will continue to heat the PR I use. I don't see how adding another step would make things any better or easier but just add one more step in which to introduce a chance for a visit from the casting demons. Just my opinion and I'm sure others will express theirs.
You could always run some tests, gather the results and report back to us. Good luck and I hope someone can be more help than I have been with your question.
Do a good turn daily!
Don
Thinning PR helps with the removal of air bubbles. Using a water bath seems to be the easiest way without purchasing more stuff. I'm not real sure heating is the preferred method (preferred as in being used by most of those who cast PR). It would be interesting to see how many casters actually heat polyester resin but I will not be setting up a poll.
I can't comment on thinning with styrene because I do not use styrene to thin. I'm not sure what the final effects on the blanks would be using PR thinned with styrene. I will not be trying it but will continue to heat the PR I use. I don't see how adding another step would make things any better or easier but just add one more step in which to introduce a chance for a visit from the casting demons. Just my opinion and I'm sure others will express theirs.
You could always run some tests, gather the results and report back to us. Good luck and I hope someone can be more help than I have been with your question.
Do a good turn daily!
Don
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NewLondon88
Local Chapter Leader
thinning with styrene tends to give a very brittle blank. It will work, but
you'd be much better served by warming the resin. It isn't hard to do,
put the resin in a container, cover it and put it in a warm bath.
Styrene fumes are nasty enough from the resin .. breathing them
undiluted isn't a great idea.
you'd be much better served by warming the resin. It isn't hard to do,
put the resin in a container, cover it and put it in a warm bath.
Styrene fumes are nasty enough from the resin .. breathing them
undiluted isn't a great idea.
Marshall Tucker
Member
Thanks for your thoughts, I've been dissolving the pearl powder in styrene before adding to the resin and it seems to work well for me, 10% at the most, I always wear a respirator to protect myself. I don't see it as another step but one used instead if the water bath. I am using pressure though. I have only cast 1 gal of Silmar. I do think it adds to more cast shrinkage though,but I'm definitely a rookie at this. I don't have a jewelry cleaner so I got the styrene when I ordered the resin.
clapiana
Member
what is your objective in thinning it with styrene?is it to save on resin?
if not you dont have to use a jewlery cleaner even though they are easy to use.
a water bath like mentioned above will work just as good to do so go get an old shallow pot put in your cup of resin with a piece of wood as a cover to hold it from floating and pour enough WARM water into the pot so 1/2 the cup is covered. wait 15 mins should do the trick
if not you dont have to use a jewlery cleaner even though they are easy to use.
a water bath like mentioned above will work just as good to do so go get an old shallow pot put in your cup of resin with a piece of wood as a cover to hold it from floating and pour enough WARM water into the pot so 1/2 the cup is covered. wait 15 mins should do the trick
Marshall Tucker
Member
I was thinning it, only 1 oz in 10 to dissolve the pearl powder and to help release the bubbles. I only figured the amount of resin when calculating the amount of mekp, 4 drops per oz. I really didn't see any adverse effects in the resin. I thinned Silmar 41 and Casting Craft resins both with it. I don't think it will increase the volume of the cured resin because all the styrene flashes off as it cures thus you get more shrinkage. I have noticed I don't get tacky surfaces anymore.
Styrene is the industry standard for thinning poly resins, up to 15% by volume. The resins are designed to be thinned with it to make them flow better and the only adverse effects I can tell are SMELL and shrinkage. I can't tell that it makes it more brittle, but I kept the resin to mekp ratio the same as without it.
It can't be any easier than to measure it and pour it in but all the searches on the forums I did I didn't find anyone using it and had to ask why not?
Styrene is the industry standard for thinning poly resins, up to 15% by volume. The resins are designed to be thinned with it to make them flow better and the only adverse effects I can tell are SMELL and shrinkage. I can't tell that it makes it more brittle, but I kept the resin to mekp ratio the same as without it.
It can't be any easier than to measure it and pour it in but all the searches on the forums I did I didn't find anyone using it and had to ask why not?
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sbell111
Member
I don't understand. You stated that you are thinning it with styrene to cut down on bubbles. You also state that you are casting with pressure. Given that pressure casting will eliminate bubbles, what's the point of the styrene.
Personally, I cast with pressure. I do not heat my resin or do anything else to avoid bubbles because the pressure does the trick.
Personally, I cast with pressure. I do not heat my resin or do anything else to avoid bubbles because the pressure does the trick.
snyiper
Member
Why not dissolve the perl in the MEKP?
marshall
Member
I too, cast with pressure. I do not heat my resin or do anything else to avoid bubbles because the pressure does the Job.
Marshall Tucker
Member
There is a great ideal, thanks!I started using styrene before I got a pressure pot and just kept using it, I'll try the next one without it.
Thanks guys, I know I'm better off not using it if I don't need to.
Freddie
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