Boat Building Forum

Find advice on all aspects of building your own kayak, canoe or any lightweight boats

Strip: two part polyurethane question
By:Al Edie
Date: 6/21/2011, 6:44 pm

Hello all,

I just put the third of four coats of Interlux Perfection Plus, a two part polyurethane on my stripper. The previous two coats went on without issue other than a few runs, and in the second coat, some skips and brush marks. No fisheyes either time. The last coat that I just completed has fisheyes. I am not amused.

Preparation for the first coat was wet sanding, wash with detergent, rinse, and then rinse with toluene and wipe dry immediately. The second coat went on with hand wet sanding of runs only, no sanding on most of the kayak. The first coat was applied with foam brushes, which worked ok as long as the brushes were discarded and replaced before the solvent did too much damage to them. Due to the reaction of the foam brushes to the solvents, I applied the second coat with a bristle brush, which worked ok except that brushmarks were left, and because I had not sanded the whole surface, it was difficult to see where the new coat had been applied, so there were also a few spots with no new coat applied.

On the third coat put on earlier today, I decided to try the roller and tip method to avoid the brushmarks issue, and I sanded the whole surface, partly to deal with the dust bits, and partly to be able to better see where the new varnish was being applied. On this third coat, I have the evil fish eyes, and I cannot figure where the devil they came from.

On coat number four, I will likely wet sand again, and go back to the dissolving foam brush technique unless someone has a better idea.

Anyway, the purpose of this note is to ask whether any of you who have used two part polyurethane have run into this issue, and whether you have any idea what has happened here. It would be nice to avoid this problem in my final coat tomorrow. I only have enough material for one more coat, so what I see will be what I get.

My ideas for the source of the problem are:

- not enough time after the water rinse to dry the surface completely, perhaps there were invisible pinholes or the like that managed to retain moisture for the hour or so that the boat sat after being wiped down after wet sanding. Same comment re. the wash with toluene, except the time to dry was much less, perhaps from 10 minutes to a half hour depending on which part of the hull.

- oil contamination from a mystery source, possibly my hands during the wet sanding, possibly the random orbital sander - I can't for the life of me think where else it could have come from.

At this point, I have to say that the two part stuff may be more trouble than it is worth. I have done lots of varnishing before, and never run into anything like the fuss that this stuff is.

Almost launched,

Allan Edie

Messages In This Thread

Strip: two part polyurethane question
Al Edie -- 6/21/2011, 6:44 pm
Re: Strip: two part polyurethane question
Mike Bielski -- 6/22/2011, 10:22 am
Re: Strip: two part polyurethane question
Al Edie -- 6/22/2011, 10:50 am
Re: Strip: two part polyurethane question
Mike Bielski -- 6/22/2011, 11:00 am
Re: Strip: two part polyurethane question
Al Edie -- 6/22/2011, 6:53 pm
Re: Strip: two part polyurethane question
Al Edie -- 6/22/2011, 7:13 pm
Re: Strip: two part polyurethane question
Dan Caouette (CSFW) -- 6/22/2011, 4:21 pm
Re: Strip: two part polyurethane question
Al Edie -- 6/22/2011, 7:09 pm
Re: Strip: two part polyurethane question
Bill Hamm -- 6/22/2011, 7:35 pm
Re: Strip: two part polyurethane question
Dan Caouette (CSFW) -- 6/23/2011, 9:26 am
Re: Strip: two part polyurethane question
Bill Hamm -- 6/23/2011, 9:53 am
Re: Strip: two part polyurethane question
Al Edie -- 6/23/2011, 10:57 am
Re: Strip: two part polyurethane question
Bill Hamm -- 6/24/2011, 7:58 am
Re: Strip: two part polyurethane question
Al Edie -- 6/24/2011, 1:09 pm
Re: Strip: two part polyurethane question
Bill Hamm -- 6/25/2011, 7:19 am
Re: Strip: two part polyurethane question
Al Edie -- 6/23/2011, 10:13 am
Re: Strip: two part polyurethane question
Bill VerSteeg -- 6/27/2011, 10:55 am
Re: Strip: two part polyurethane question
Bill Hamm -- 6/28/2011, 2:56 am
Re: Strip: two part polyurethane question
Dan Caouette (CSFW) -- 6/23/2011, 9:40 am
Re: Strip: two part polyurethane question
Al Edie -- 6/23/2011, 11:09 am
Re: Strip: two part polyurethane question
Bryan Kapteyn -- 6/23/2011, 11:44 am
Re: Strip: two part polyurethane question
Al Edie -- 6/23/2011, 4:13 pm
Re: Strip: two part polyurethane question
Bryan Kapteyn -- 6/23/2011, 4:37 pm
Re: Strip: two part polyurethane question
Al Edie -- 6/24/2011, 1:17 pm
Re: Strip: two part polyurethane question
Bill Hamm -- 6/25/2011, 7:24 am
Re: Strip: two part polyurethane question
Bill Hamm -- 6/24/2011, 8:02 am
Re: Strip: two part polyurethane question
Kevin McAtee -- 6/28/2011, 2:59 pm
Re: Strip: two part polyurethane question
Al Edie -- 6/22/2011, 7:19 pm
Re: Strip: two part polyurethane question
Mike Bielski -- 6/24/2011, 12:22 am
update, last coat
Al Edie -- 6/23/2011, 1:19 pm
Re: update, last coat
Dave Houser -- 6/23/2011, 3:18 pm
Re: update, last coat
Al Edie -- 6/23/2011, 4:19 pm
Re: update, last coat
Bill Hamm -- 6/24/2011, 8:05 am