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Re: Strip: two part polyurethane question
By:Al Edie
Date: 6/22/2011, 10:50 am
In Response To: Re: Strip: two part polyurethane question (Mike Bielski)

Hi Mike,

Thanks for the reply, I appreciate your taking the time. Since my last post, I did a search on the internet on this topic, and it seems more or less certain that the problem is contamination of the surface with stearates, silicone, or oil. I also had a look at a few of the fisheyes under magnification, and there is no hint of pinholes in any of the ones I checked. They just look like dry spots to which the finish would not adhere, which is consistent with the notion of contamination. There would not have been any roller bubbles from coats numbers one and two, because neither of these coats used rollers.

Anyway, the main differences between the first two coats without fisheyes and the last one with them are first, no detergent wash after using the sander, unlike coat one, and second, the use of my random orbital sander, unlike coat number two. I was suspicious that some lubricant had made it out of the pad bearing which I had to work on earlier and re-lubricate. I pulled the sander apart, and there were signs of grease having worked its way out of the bearing and into the wet sanding slag on the inside of the sanding pad assembly. Right now, I suspect that this grease is the culprit. I will scrub the kayak with detergent before and after the wet sand this morning, and I have now thoroughly cleaned the sander and removed sufficient lube from the bearing that it should not cast any more grease. After that, I will apply my last coat and see what happens. If it works fine, I am done, if not, I will have to buy another quart of this stuff and do some serious sanding later. Right now, I need to get this thing done and in the water because my wife and I are heading out on a boat trip with the kayaks on deck shortly.

I will let you know what happens later today.

Thanks again for the advice,

Best regards,

Allan Edie

ps. By the way, you are right about the bubbles from the roller, there are lots of them when you check under magnification, invisible to my bare eye, but they are there.

Hey Allan- tha

: First, call the manufacturer's tech support. They're probably the
: best advice about their specific product, particularly when it
: comes to the dissolving foam brush. I would try to avoid that
: because it could interfere with the long-term integrity of the
: product.

: Now- pinholes and fisheye look very similar. My guess is that you
: have pinholes, not fisheyes.

: Unless you had mystery overspray from silicone aerosol or WD40 or
: something, your prep should be enough to avoid fisheyes even if
: you were sloppy. Rolling on a finish is much more likely to
: introduce bubbles than brushing. It's almost a given that using
: a roller will introduce bubbles even if you don't see them
: easily, and they won't pop even if you tip it off. When you sand
: for the next coat you break through the finish on top of the
: bubble and open up the pinhole. The reason it was a bigger
: problem than normal is that two parts cure faster than
: traditional varnish, making them more likely to trap air, and
: they're not as high solids as traditional varnish and start to
: cure much faster, so you don't get any filling of the pinholes
: on the subsequent coat like you would with a varnish.

: Your solution is probably just to sand until you get rid of the
: defect, which should be two coats of finish. Then just get back
: to it, but use a brush. When you talk to the tech line, ask what
: they recommend for a brush. They'll probably also be able to
: confirm whether it's pinholes of fisheye. If they think it is
: fisheye, there is an anti-fisheye additive for 2-part commercial
: wood finishes that you can add, and you should ask them about it
: and whether it would work with this product.

: Also- be aware that even an automotive finish applied by a
: professional is not "perfect" until they wet sand and
: buff. Likely, your harder 2-part will be the same. You'll either
: have to live with brush marks, or wet sand and buff to get rid
: of them.

: Good luck- you'll get it in the water.

: m

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