How to tell epoxy from polyester

[gmarker]

I am going to start restoration on a 16 ft 1969 Kenner Fishing /Ski Barge. It seems to be a simple little boat, so I thought this would be a good project to get my feet wet. It has apparently had the deck replaced in the past. Everything seems solid. However, based on the obviously amature way the deck was glassed, I intend to cut it out and see what else may need to be redone. The deck and halfway up the sides have been glassed with woven roving and painted with what I suspect is house paint. In any case, it needs to come out and be redone properly. I have spent several hours reading posts on this forum and feel confident that I can do whatever needs to be done (maybe with an occassional question to you fiberglassing gurus). Before I start I have two questions that I hope someone can answer.

1. Is there any way I can tell for sure whether the the PO used polyester? I know it was built with polyester, but I
understand that polyester can't be used over an epoxy repair. Can someone clarify this for me.
2. The entire inside of the hull was painted with what looks like house paint. Can I use a paint stripper on this without
damaging the fiberglass? If not, are there any other suggestions besides sanding.

Thanks for any suggestions or info.

 

[ondarvr]

Re: How to tell epoxy from polyester

For someone very familiar with the two products it can be somewhat easy (sometimes) to tell the difference, but to a rookie they look the same. The harder it is to sand, the more likely it's epoxy, but since you haven't sanded on either one won't know the difference. Chances are it polyester though.

There are strippers that will work on the paint and not hurt the resin.

 

[Three08]

Re: How to tell epoxy from polyester

I'm going to hire a soda blaster the strip the paint on my hull, it's meant to get the paint off easily and not damage the fiberglass.

 

[chriscraft254]

Re: How to tell epoxy from polyester

I'm going to hire a soda blaster the strip the paint on my hull, it's meant to get the paint off easily and not damage the fiberglass.

Be very careful in picking the right soda blaster guy. To much pressure and not enough patience and he can damage the gelcoat.

 

[Three08]

Re: How to tell epoxy from polyester

Be very careful in picking the right soda blaster guy. To much pressure and not enough patience and he can damage the gelcoat.

Thanks for the tip, I'm only doing the inside of the hull with the soda blaster to prepare for the transom and deck tabbing, the texture of the glass makes it impossible to sand back and remove all the paint without taking half the glass off aswell. Now I know to tape off all the gelcoat first.

 

[Woodonglass]

Re: How to tell epoxy from polyester

Uhhmmm, I'd really recommend you grind the paint and glass on the inside around the transom with a 4 1/2" grinder and 36 grit sanding discs. This will ensure that you get down to fresh glass. The soda blasting, IMHO, is expensive and not the way to do it. Not saying you can't, just that the conventinonal grinding method would probably be better.

 

[gmarker]

Re: How to tell epoxy from polyester

Thanks for the replies. I guess grinding is what it will be. I have considered soda blasting, but would prefer to do all the work myself. That way if it turns out bad I have only myself to blame and I might even learn something. This project is going to get a slow start as I have other projects under way at the same time. I can't imagine how I ever found time to work for a living. Some advice for those looking forward to retirement. If you want to spend your time just fishing and loafing, you had better sell all of your tools, move far away from all relatives, and get a divorce. Otherwise, you will quickly find out what being too busy really is. ---------- On the other hand, LIFE IS GOOD. Happy boating eveyone!

 

[Three08]

Re: How to tell epoxy from polyester

gmarker
Make sure you get a good respirator, that stuff is real bad for your lungs. Post some pictures if you can and you should think about starting a rebuild thread, you tend to get more input when the whole project is there in the one place.

Woodonglass
Thanks for the input, I was planning to soda blast then fill the low spots with pb and then sand as i thought i would need to take a lot of glass off to get down to the paint in the low spots, the paint has been put straight over what looks like chopper gun roving, it's very uneven. I had another look today and i think i can get away with sanding it all out, what I do take off should be replaced once the skins go on, i guess the texture just looked deeper when I'd been sanding all day.

 

[Woodonglass]

Re: How to tell epoxy from polyester

Not sure what you "Down Under" guys are using but up here in the States we use this to Grind the glass... Full face respirator ARE a must. Full cover Tyvek suits and don't forget to coat yourself in baby powder before suiting up. It REALLY helps keep the ITCH off of you. G'Day Mates!!!!

 

[gmarker]

Re: How to tell epoxy from polyester

gmarker
Make sure you get a good respirator, that stuff is real bad for your lungs. Post some pictures if you can and you should think about starting a rebuild thread, you tend to get more input when the whole project is there in the one place.

Three08,
I appreciate the advice. I'll be wearing the full protective gear since I'd like to live long enough to to enjoy the completed project. I will start a rebuild thread as soon as I start taking things apart. Still have to get some other things done before I can devote time to the boat. The wife says her "honey do list" takes priority, and since I've had her longer then I've had the boat, I guess she's right.