Epoxy Hull painting

[Mr Hands]

Hi All,
My dad gave me his '70 Alumacraft w/ a newer Erude 130. Already replaced the stringers deck, gauges & wiring.
I am nearing the end of repairing some hull damage. I have ground down the bad spots at the bow and re-patched a few poorly done repairs with layered fiberglass mat / epoxy and filled in with bondo to make nice & smooth then one last layer of glass.
The rest of the bottom is 3 layers of peeling paint. I will sand down the paint to a single solid surface and probably coat with epoxy.
Should I layup the entire bottom glass mat & epoxy?
The boat is trailered and only occasionally used during summer months in fresh water.
Does the epoxy NEED to get painted?
Ca it just get waxed?
If it needs paint, what is a cost effective paint to use?
THNX!

 

[glennrow]

Re: Epoxy Hull painting

Hi All,
My dad gave me his '70 Alumacraft w/ a newer Erude 130. Already replaced the stringers deck, gauges & wiring.
I am nearing the end of repairing some hull damage. I have ground down the bad spots at the bow and re-patched a few poorly done repairs with layered fiberglass mat / epoxy and filled in with bondo to make nice & smooth then one last layer of glass.
The rest of the bottom is 3 layers of peeling paint. I will sand down the paint to a single solid surface and probably coat with epoxy.
Should I layup the entire bottom glass mat & epoxy?
The boat is trailered and only occasionally used during summer months in fresh water.
Does the epoxy NEED to get painted?
Ca it just get waxed?
If it needs paint, what is a cost effective paint to use?
THNX!

 

[glennrow]

Re: Epoxy Hull painting

if you have gone through so much repair already, why not finish it off right. i found a marine paint through west marine and i believe its called interflux..its easy to put on by hand ( no need for a sprayer ) and requires no mixing..you apply it with a roller and follow it up with a foam brush....as soon as you put it on you see ugly streaks and brush marks - but after about 20 minutes they dissapear and leave a beautiful looking paint job..does not cost much at all...sorry about the blank reply earlier...good luck....i used this paint with my 1947 oday sailboat and 91 bayliner this spring...good stuff

 

[oncebitten]

Re: Epoxy Hull painting

If this is a fiberglass hull, Glenrow is right, Interlux is a good quality affordable marine top-side paint. I like S3 products too, but they tend to be a bit more expensive. A couple things should be mentioned.

1. Epoxy- you mention Bondo, which is polyester resin as far as I know, not epoxy. Epoxy resins will stick to polyester resins, but polyester will not stick to epoxy (for long), so make sure you're using the right stuff in the right order. (if you're using polyester resins, listen to someone else because I don't know much about them accept that they're not as "water-proof" as epoxy resins) Back to the comment... if you're using epoxy, it needs to be coated with something with UV inhibitors, otherwise, the sun will damage it.

2. Top side Interlux should be fine for the bottom of this hull since it doesn't sit in the water and it is trailered. If it were going to sit in water for longer than a day or two, or if it will see salt water use regularly, you should consider anti-fouling bottom paint.

3. I wouldn't bother laying on more glass and epoxy if the original structure is in tact except for the few holes you already repaired. Just fair them into the hull and give it a good prime and paint. Extra glass and resins will just add weight. If the original hull structure is in good shape, you shouldn't need to do that.

4. Do a google searches for boat plans. You'll find a lot of online information about stitch-n-glue boat building, and repair techniques from which you can gleen tons of valuable information about your own repair projects.

Good luck with the boat.

 

[Mr Hands]

Re: Epoxy Hull painting

If this is a fiberglass hull, Glenrow is right, Interlux is a good quality affordable marine top-side paint. I like S3 products too, but they tend to be a bit more expensive. A couple things should be mentioned.

1. Epoxy- you mention Bondo, which is polyester resin as far as I know, not epoxy. Epoxy resins will stick to polyester resins, but polyester will not stick to epoxy (for long), so make sure you're using the right stuff in the right order. (if you're using polyester resins, listen to someone else because I don't know much about them accept that they're not as "water-proof" as epoxy resins) Back to the comment... if you're using epoxy, it needs to be coated with something with UV inhibitors, otherwise, the sun will damage it.

2. Top side Interlux should be fine for the bottom of this hull since it doesn't sit in the water and it is trailered. If it were going to sit in water for longer than a day or two, or if it will see salt water use regularly, you should consider anti-fouling bottom paint.

3. I wouldn't bother laying on more glass and epoxy if the original structure is in tact except for the few holes you already repaired. Just fair them into the hull and give it a good prime and paint. Extra glass and resins will just add weight. If the original hull structure is in good shape, you shouldn't need to do that.

4. Do a google searches for boat plans. You'll find a lot of online information about stitch-n-glue boat building, and repair techniques from which you can gleen tons of valuable information about your own repair projects.

Good luck with the boat.

This is below the waterline...

 

[ondarvr]

Re: Epoxy Hull painting

Is your Alumicraft aluminum or Fiberglass?

 

[Mr Hands]

Re: Epoxy Hull painting

Is your Alumicraft aluminum or Fiberglass?

It is a fiberglas AlumaCraft - they only made for a few years, before going back to all aluminum. I guess its a classic.

 

[oncebitten]

Re: Epoxy Hull painting

It's okay that it's below the waterline, the critical questions are whether or not the boat will sit in the water for prolonged periods and whether it will be in salt water. If it's going to sit in the water for more than a couple days, get the opinion of the paint mfg. first.

Even though the paints are called top-sides paints, they are generally okay if the boat is going to be trailered. I painted my boats with S3 top-side linear polyurethane paints and they're 4-years old and 2-years old and they polish up like the day I painted them on the outside. The inside whites tend to stain from all the use, and they need to be freshened up every few years. You can try going to the mfg website and asking their tech support first. Interlux, which is not the name of the company, I can't remember what the company name is, something like International Coatings or something like that, must have tech support like S3 does.

As far as resins below the waterline- I only use epoxy resins regardless, even in auto-body work (not my field, but I always seem to buy POS trucks that need some body work).