Barrier Coat/Primer re-coating question

[Idon84]

I notice that epoxy really turns yellow fast in the sunlight after filling holes etc. To what degree the yellow signifies degradation of the epoxy I don't know. I try to keep those areas covered to limit UV. On my bobstay for instance I have covered the area around it that I built up out of thickened epoxy with just some cheap house primer until I can get around to completely painting it.

I was intending on barrier coating my hull before it gets cold this year but just notice that the Interprotect 2000E I bought says that I have to apply anti fouling paint within a 24 hour window of my last coat of primer. If I want to put another coat of primer, max re-coat window is 6 months making it a tight schedule because March in the PNW is still too cool.

I'm no where near launching and plan on working through another warm season in 2010 to finish the exterior paint, non skid etc. I was hoping to do the barrier coat then put on the primer to limit the UV exposure while waiting to finish other tasks but that doesn't seem to be a viable option. Short of covering the entire hull for the winter after the barrier coat is there anything I can apply that I would not have to sand completely off before applying the interprotect 2000E and then the anti fouling before launch? I would think that just leaving a fresh barrier coating sitting in the sun (little sun in the winter though) would be a bad thing but I haven't a clue.

I guess I could wait until closer to launching as an option but I had the time all figured out, a crew assembled, many foam rollers and what I thought were the materials to keep it protected until I could finish the rest of the boat. Should have read the directions better I guess. My Bad! Am I making any sense here?

Thoughts?

[Tim]

Why not just apply a coat of bottom paint over the barrier coat when it's complete, thus maintaining the proper 24-hour application window? This will take care of the problem easily and effectively.

[Hirilondë]

If I recall correctly the 24 hours between Interprotect and bottom paint refers to the hot coat period. After 24 hours you would have to sand before bottom paint. There is also a hot recoat period for Interprotect within which you can do another coat of Interprotect without sanding. I recall that being 2 weeks. I don't remember any limit to how long the Interprotect can can left exposed, just that it will require sanding before what ever is next after the time limits.

[Tim]

I think it requires sanding and a new coat of Interprotect if it sits longer than 24 hours, and then overcoating within the 24-hour window at that time; this is based on my recollection of the product instructions on the can from the one time I used the product, but I can't find this specific information online at this time to confirm. But it was clear from the instructions on the can.

It sure seems a lot easier to just put the bottom paint right on and I can't imagine why one wouldn't.

[Idon84]

I guess I will try to get in touch with Interlux about the question. The coat time is for bottom paint is within 24 hours. I was thinking of putting on 1 coat of the primer and then waiting to do the next when I closer to putting on the bottom paint but it says there is a max re-coat time between primer coats to 6 months. I don't know what this means. I would think I could just give it a sanding and apply additional coats of primer after the fact but I'll have to check on exposure issues.

Thanks,

[Idon84]

I'm going to wait until next spring and do it all at once. Seems the most logical and It's best to follow directions I would think. Besides I have a lot of other things to do and the helper crew would be fine with waiting.

Thanks again.

[Idon84]

UPDATE: (and another question)

So I've been using Interprotect 2000E to my 5th coat thus far. Good stuff, easy to work with, nasty smelling but covers well etc. I did call interlux and the guy I spoke with said 6 months for re-coat without sanding. I read the instructions on the can and just as Hirilondë mentions above, it says there is a 2 week period for re-coating without sanding. Slight contradiction. I'm sticking to the 2 week window to be safe.

Anyway, my question: Beading the through hulls...

-Bead onto interprotect coat #5 before applying coat #6 to hot coat bottom paint or,

-Bead onto bottom paint?

Will be using Pettit Vivid

Thanks again for the great advice!

[Hirilondë]

Anyway, my question: Beading the through hulls...

-Bead onto interprotect coat #5 before applying coat #6 to hot coat bottom paint or,

-Bead onto bottom paint?

I don't know enough about the chemistry of the Interprotect to know what effect there might be of bedding to a partially cured material. But I can't think of any advantage it might have either. I do know that bottom paint is not the best surface to bed to. I know that bedding to a fully cured hard paint with Sikaflex or similar works really well. I would choose to bed to coat #5.

[Idon84]

Thanks Hirilondë,

Called Interlux help line again and they confirmed that as well. I'm really liking that 800 tech help number.

Cheers,