Resin safety question

rucaradio

Petty Officer 2nd Class
Joined
Aug 23, 2008
Messages
184
Perhaps this has been addressed in this forum before and if it has, pardon the repeat.

I'm planning on glassing in my new transom tomorrow and stopped by Lowes to pick up a few things (nitril gloves, new respirator, stir sticks, etc). I'm going poly and have read it is pretty nasty stuff.

I've read that quite a few people recommend mixing the resin and hardener with a drill-chuck paint mixer. I had planned on doing this myself, but noticed on the package a big "Caution - NOT FOR FLAMMABLE LIQUIDS". Reading the packaging more, it mentioned how sparks caused by drills could ignite flammable substances.

Question is maybe these drill stirrers are fine for epoxy, but are they dangerous to use when mixing up poly?
 

88BLiner

Petty Officer 2nd Class
Joined
Mar 22, 2009
Messages
172
Re: Resin safety question

From all the info that I have read on this great site mostly everybody just uses the stir sticks because you should only be mixing small amounts at a time so it does not cure before you can use it all. You will have plenty of time to mix these small amounts by hand before it starts to cure. I have been making 16 to 20 oz batches and if I run out I just mix up another batch. As long as you don't wait for hours before you start using the second small batch you will still get a good chemical bond between the first and second batches. Better to be safe than sorry!
 
Last edited:

PiratePast40

Lieutenant Commander
Joined
Mar 21, 2009
Messages
1,734
Re: Resin safety question

88BLiner is right - you shouldn't be mixing up large batches so stir sticks will be fine. Do yourself a favor and try a few batches on a separate surface to see how fast it hardens. Then you'll get a good feeling for your working time.

You mentioned getting new cartridges for your respirator. You should have purchased the cartridges with the balck stripe. Those are carbon catridges and are for gasses. The ones with and magenta stripes are for particulates.
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: Resin safety question

Hello Radio..

1. your drill would not ignite any volatile gas in the resin.

2. Never use an electric paddle mixer to stir your resins..especially poly ! It will create friction within the mix and shorten your pot life. stir sticks are juust fine m8. ( I use tongue depressors for small batches ).

The ONLY time I use a power mixer is when Im doing a big fill job with epoxy that I need to make into a filler. You need to mix the epoxy B4 you add any filling agent IE. Cabosil. OR making a large batch of POLY filler for future use ( with cabosil but without hardener ).

YD.
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: Resin safety question

USing a jiffy mixer in a drill is for mixing seacast, thats what you read here.
Its thick and heavy like mud with rubble in it.

I never work indoors so I don't use the mask with poly,
epoxy is far worse as far as body chemistry goes, something a lot of people don't realize because the poly stinks and epoxy doesn't.

I mix poly with the brush I'm using (and re-using and re-using), never had a failed batch in yrs. Putty needs a stick or blade to mix.

Half a gallon is the biggest batch I'm comfortable with, with bigger batches just be sure to get it out of the mixing pail immediately, I pour it on to the work surface to keep the heat down. If you plan the work and don't fiddle around theres plenty of time to get it right and get the brush into acetone.
 

4runneradam

Petty Officer 1st Class
Joined
May 7, 2007
Messages
203
Re: Resin safety question

Poly resin isnt that bad. Just work outside (IN THE SHADE) and its no problem at all. Spray painting is much more smelly and flammable than the resin.

Mix SMALL batches at a time. I have been doing 4-8oz. I got one of those wide spatulas designed to mix bondo, and cut them up in strips to use as a stirer. You can re-use it even after the resin hardens.

The little plastic dome that covers the resin can and holds the hardner is a great mixing container. After it hardens you can just pop the resin out with no residue left behind and reuse it.
 
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