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Author
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Topic: Does Resin need Oxygen?
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y
unregistered
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posted 12-10-2003 11:32 PM
does polyester resin (the casting resin which you mix a catalyst for it to harden) need oxygen for it to solidify?im asking because i want to put my mold in an air tight container so that i dont have to inhale the fumes while it's reacting...
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anaerobe
unregistered
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posted 12-11-2003 11:13 AM
no oxygen is needed. that is why you added the catalyst to the resin. but rather than put it in an air tight container, try leaving it in a well-ventilated area or even outside in a protected enclosure....IP: Logged |
polly & her sister ester
unregistered
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posted 12-11-2003 12:35 PM
Actually, putting it in an airtight container would hinter the crosslink process(somewhat). The styrene wants to leave during crosslink and if it can't the whole reaction slows down.The wholre reaction takes place in forty minutes or so (depending on the percentage of cataylization). Once that is over you could put it in a snowbank if you wanted to. The well ventilated area is your best bet. And don't forget the cup you mixed the batch it in either.
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y
unregistered
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posted 12-11-2003 06:53 PM
oh, thanks for your replies  i forgot to mention, im also putting it in an airtight container so that i can bring it inside where it it WARMER. leaving it outside (which is MY equivalent to a "well ventilated area") it is much too cold during the winter time for the resin to react properly/quickly... i've read that resin ideally needs the temperature to be 20C.... any suggestions? inside for 30 mins, outside for 30 mins?
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gluBOY
unregistered
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posted 12-12-2003 12:34 PM
you mentioned polyester CASTING resin.unless it's an issue of transparency, why aren't you using polyurethane casting material? it kicks much faster. if you are LAMINATING poly and fiberglas you can "flash" it with sunlight (UV) for ten or fifteen minutes and it will continue to crosslink at 32F. if you will be doing alot of this you could build a "curing oven" using scrap plywood, fiberglas insulation, and a couple of 100W light bulbs for that matter and leave it outside. at any rate, your material should be WELL cured by now.... :-) IP: Logged |
y
unregistered
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posted 12-13-2003 12:42 AM
oh yes, it is an issue of transparancy. i use water-clear casting resin only.im just concerned how much this air-tight container idea will hinder the crosslink process...
what is styrene exactly? ive tried my idea for the last couple of days. it seems okay... IP: Logged |
gluboy
unregistered
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posted 12-18-2003 12:13 PM
a question y,are you using RTV (room temp. vulcanizing; silicone)for your molds? if so, are you experiencing a highly "crackled" surface finish (resembles a "crackled" faux paint appearance, only in 3d) caused by the resin shrinking away from the mold surface as it cures. just wondering. my clear parts require much sanding and polishing (to remove the surface "crackles") before they are truly "clear". IP: Logged |
y
unregistered
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posted 01-02-2004 08:28 PM
hello glueboy,
sorry for the late reply! hope everyone is having a splendid holiday!i am unfamiliar as to what RTV is. is it those flexible silicone molds? if so, i think i have had that problem but i thought it was because the mold may have not been very smooth... perhaps it WAS because it was shrinking away from the mold... i think there are different types of resins that have different ratios of shrink-age... sorry, im not near my resin notes to be more informative! IP: Logged |
gluBOY
unregistered
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posted 01-05-2004 03:20 PM
R = room
T = temperature
V = vulcanizing (hardening of a rubber-like material; a term that i believe is atributed to BF Goodrich, the tire guy)yep, it's the same stuff, just a more tech-nickle name for it. i've tried several casting resins and always seem to get the same "crackley" finish... if i could just come up with some cutsie item that utilized that surface finish i'd be in the fat. i don't get the crackles when i use a "solid" mold material (like plaster or cast urethane)... but the undercuts are a bitch (multi-piece molds, etc.)...maybe the mold surface is "giving" and is pulled as the resin cures ... i dunno... IP: Logged |
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