Paint-how to determine what paint was used?

[Crazer]

So I'm sure we've all had to deal with this at some point, but I want to refinish my boat and need to know what type of paint is already on the hull. The paint that is there is in pretty good shape and so I don't see an need to take it all off for refinishing. So, is there some way, any way, that I could find out what type of paint is already on the hull? I could ask the previous owner but I know the boat was last refinished before he got it so it's unlikely he would know unless he thought to ask the owner before him. In my mind I imagine sending a paint sample off to a labratory and having them tell me what it is, but this is likely pure fantasy.

[earlylight]

Most manufacturers of marine paints (ie: Interlux), have excellent web sites advising what kind of primers, tie-coats etc are needed for their topside paints. Some have an "ask the experts" link available to answer your questions. If you know what product you wish to use for your topside painting, they should be able to guide you through the required steps. That's where I would start if I was not sure of the paint that is on the hull now.
Good luck and keep us posted.

[Crazer]

Thanks for the suggestion, I guess I'll just start there. I was hoping for some kind of "silver bullet" solution (there never is one) but knowing where you're going is just as important as where your starting from. Now I've just got to sort through all the possible options and decide which to go with...:sigh:...

[galleywench]

I just went through a similar exercise earlier this year on a small part of my deck that had original paint on it. I had planned on using a 2 part paint (Interlux Perfection) and the product literature stated that it shouldn't be applied over an enamel or other 1 part paints. I wasn't sure what the original paint was but wasn't having much luck sanding it off so I spoke with an Interlux rep. who told me to do an MEK Test (or solvent test, I think MEK stands for Methyl Ethyl Ketone).

The test was simple, saturate a rag or paper towel (~ 1 inch square) with Interlux 2333N Brushing Reducer (I'm sure there are plenty of other solvents with MEK in them that would do the trick as well) and tape it to the painted surface in question with a plastic baggie over it so the solvent doesn't evaporate. Leave it on overnight and if the underlying paint is not soft and mushy the next day, you can paint over it with a 2 part paint.

I have a photo or 2 here:
http://www.alberg35.com/2012/06/ready-f ... me_29.html

Hope this helps.