Bottom paint gone bad?

[s/v Faith]

I have a line on 2 gallons of Pettit Horizons bottom paint for a real good price.  The paint is about 5 years old.

IIRC, bottom paint is ok as long as it has not frozen.... any way to tell?  Any one know for certain?

I tried calling Pettit, and so far they have not gotten back to me.  They are closed for the day, and I am supposed to meet the guy tomorrow.... thinking I will pass unless anyone has an answer here.

[Tim]

Can you look at it? Stir it? I am pretty sure if you can get it to mix it is still good.

[tomwatt]

Try to see if your local paint store will put it on one of their shakers for about 2 minutes... you'll never be able to do with stirring what the shaker can do in two minutes, then pop the top... if it was frozen, it will look more like cottage cheese than paint (lumpy, clotted, etc.), then check the smell - sometimes paints will go sour and spoil. If still seems okay, dry out a test patch. If all still seems good, paint your bottom!
(I've been dieing to use that line!)
;D

[CharlieJ]

Many paint shakers won't shake bottom paint. Many stores will refuse also-  too heavy for most shakers, without damaging the shaker.

We couldn't even shake our own when Laura was working in a store with a paint dept, and shakers.

A drill powered stirrer would be best. Use a BIG drill.

[tomwatt]

Good point Charlie. It takes a heavy-duty shaker to do it... the store I'm in has them, and we shake traffic zone marking paint routinely (among the heaviest paints on the market). But if you go the drill stirring route, monitor your drill carefully or you'll burn it up.

[s/v Faith]

Many paint shakers won't shake bottom paint. Many stores will refuse also-  too heavy for most shakers, without damaging the shaker.

We couldn't even shake our own when Laura was working in a store with a paint dept, and shakers.

A drill powered stirrer would be best. Use a BIG drill.

Any experience with using bottom paint that is 5 years old?  Ever hear the thing about not letting it freeze?

[tomwatt]

Any experience with using bottom paint that is 5 years old?  Ever hear the thing about not letting it freeze?

None myself. However, all paint has a shelf life... for water-based materials it goes bad somewhere between 5 & 7 years old - I seldom see paint older than that surviving. Oil/solvent based material has a more complicated shelf life: conventional (old fashioned) oils lasting decades, some of the more exotic materials are only good for a year or so (those usually feature high-flash thinners like xylene or acetone).
Freezing a water-based material interferes with the emulsion that makes it work as paint, so you end up with something like lumpy cottage cheese.
I have yet to encounter a material that we cannot put in the shaker, although I know many paint companies don't want to shake paint that is not theirs simply because of the annoyance factor. Most modern shakers will handle the weight just fine - I have some primers & traffic marking paint that is more than twice the weight per gallon of ordinary paint. I have paint contractors bring in all sorts of things asking to have it shaken, the only trouble we ever encounter is lids that leak, but I also have shakers that will do 5 gallon pails too.
Just my 2 cents!

[s/v Faith]

Well,

  I went to pick up the paint this afternoon.  The cans were a little rusty, but looked ok.  I opened one, and there was nothing like 'cottage cheese' in it so I paid for them and took them to my friend at the paint store.

  He warned me that the shaker would generate heat in the paint (apparently the high metallic content makes lots of friction).  He put a stir in before shaking, and found 4" of solids at the bottom of the cans.  After a couple tries he got them ballenced in the shaker.  He double bagged them in case of a blow out... the Benjamen Moore heavy duty paint shaker was up to the task.

The 3/4 gallon of Easypoxy (1 part poly) shook out fine, not sure what I will use it for since it is black.... but it was thrown in with the rest so I guess it is good.

He shook the bottom paint for about 5 minutes, when it came out one of the cans had blown it's seam on the bottom... not much paint had come out.   The other can was opened and it looks good.  There is still about 1/2" of stuff on the bottom that needs to be mixed in but I think I can do that with a drill operated paddle (like I normally do with bottom paint).

It did not smell bad, and I think it will be fine.  Will update when I haul out and do the bottom.  Thanks for the input.

[tomwatt]

Sounds like you're going to be fine... although I would reiterate that a test patch off the boat someplace (to check to make sure it actually will dry, etc.) would be wise. Beats having to scrape/stip off some kind of malfunctioning goo (although based on what you describe it sounds like you're going to be "good to go"). If you have remainder you want to store, you can buy an empty paint can from the paint store and pour it up into that.
Congrats on what sounds like a good find!

[CharlieJ]

so is Rose painting fish again?