Tiny bubbles

[I33]

No, not the song, its my Bristol finish on a hatch cover. Granted I am inexperienced, but this looks terrible!

I sanded the hatch, took off all the old varnish, applied 2 coats of clear epoxy and buffed that up with 220 grit. Wiped off dust with a tack cloth.
I followed the Bristol finish instructions on mixing up the 8:1--measured very carefully. Used a brand new brush. 72-degrees, bright sunshine and I noticed the brush beginning to drag before I was finished covering the hatch. This stuff is supposed to have a 2 hour pot life! Could the sunlight have heated up the wood enough to make this stuff go off early? Any ideas would be appreciated.

As an aside, I have another hatch cover I did with straight Minwax Urethane Spar Varnish from Wal Mart!, and it looks beautiful. Makes me wonder about this "Marine" labeled stuff!

Thanks.

[JohnRPollard]

Generally not a good idea to apply finishes in direct sunlight. Shade is best, even better with temperatures on the decline (i.e. apply in the late afternoon as ambient temps are going down). Bubbling is one of the side effects of applying finish in direct sunlight.

However, that said, I have given up on 2-part finishes after having a similar "bubbling" experience on the teak companionway wash boards that I had painstakingly prepped (stripped, sanded, scrubbed, etc). They were not in direct sunlight.

Varnish or Cetol for me now -- no more mixing concoctions and risking getting the exact ratios incorrect.

[brak]

I second Cetol. Just painted a few items (new bases for nav lights and anchor roller) - easy, quick, holds well. Just don't get it onto other things - it's hard to remove once cured (but turpentine clears it up while still fresh). No bubbles either - it is fairly viscous liquid.

[Freesail99]

I find that the foam brushes cause tiny bubbles.

[LarryandSusanMacDonald]

Okay, this is what I do all day. Apply varnish, cetol, etc. Here has been my experience:

1. Bristol finish we have had problems with. Several years ago we put it on a boat with lots of teak - it looked great! For about two months. Then it started peeling and lifting. We called in the factory rep. He had all kinds of comments: teak too wet: (it wasn't), applied too cold: (it wasn't), mixed wrong: (doubtful - hard to prove). Long story short - we stripped the whole job - tedious with a two part, sanded it smooth and started again - everybody checked everything - the mix, the application, the wetness of the teak - another two months and it started to lift again. We haven't used the stuff since - maybe we got a couple of bad batches - hard to say, but we don't use it anymore and advise customers against it.

2. Cetol: Good stuff in its place - we use it a lot on older boats where the teak is losing it's bedding. Varnish just won't hold if water can get under the edge. (When we have to varnish, we even tape back about a sixteenth of an inch or so and sand out that area on the gelcoat and let the varnish seal - it helps for awhile - but eventually...) My main complaint about cetol is the color - it looks like baby ****. (Those who are parents among you will know the color.) However - cetol recently came out with a color they call TEAK - we made up a sample board - cetol, cetol light (baby **** with fewer calories) teak, and Cetol gloss. The 'teak' doesn't look bad. I'm applying it on the toe rail this week (weather permitting) of a boat I stripped last week.

3. In any case, using the cetol gloss over cetol, to me is just plain silly. Regular varnish looks 1000% better,(alright, I exaggerate, 937% better - I worked it out on my calculator) lasts just as long, applies the same way, and requires the same maintenance.

4. Here's a hint: the next time a female member of your crew empties a fingernail polish bottle, have her donate it to the boat - clean it out with acetone and fill it with the varnish that you use. Anytime you see a ding, nick, or scratch in your varnish, get out your fingernail polish jar. Open it (required step one), apply it with the conveniently supplied brush contained within to the nick, ding, scratch or abrasion. You can do it with one hand while the other contains your choice of libations (rum works best in this case - color coordination.) Recap it - (the varnish - not the rum) and settle back and sip the rum while you watch the varnish dry. Many discussions may ensue regarding the best way to watch varnish dry while sipping on your rum - let me know if you come up with any new methods.

5. If you use cetol, here's a time saver: after sanding, taping, cleaning, etc. apply a coat. Depending on temperature, breeze, direct sunlight, etc. you can wait approximately 45 minutes to three or four hours. When it is just dry to the touch (touch with your knuckle and it doesn't feel sticky, but slide your finger along it and it drags) you can apply a second coat without sanding between coats. Same thing with a third if conditions are just right. Don't push it though. If it isn't right, wait and sand and apply the next coat the next day. Many times I've managed to get three coats down in one day. The trick is, you're getting a chemical bond as opposed to a mechanical bond when you sand. The drawback is, you have to make sure you get complete coverage - it's hard to tell where you left off on the last brush stroke without the sanding.

6. As Brak said, be careful you don't get the cetol on the gelcoat - especially if it is older gelcoat. I carry a rag at all times and have alcohol, mineral spirits, or turpentine and clean up any spatters or spills immediately.

7. When you're finished and the cetol, varnish or whatever has dried, pull the tape carefully and at kind of an oblique angle to your finish so it doesn't tear out the finish. If it looks like it's going to be a problem, a razor, an exacto knife, or a utility knife run along the edge of the tape as you pull it can help. Then when you're finished, dress the edges of any finish that has seeped under the tape onto the gelcoat with a rag saturated with mineral spirits (or whatever). A sharp, clean edge looks so much more professional.

I could go on for another page or two with stuff we know about this, but you'd be bored to tears. Good luck.

[sailaway21]

Good post, Larry and Suzi!

I33,
You'll like that Helmsman Urethane Spar Varnish for about a year or so. Then it will start lifting in sheets. It will appear like sheets of celophane. The amount of effort to remove the rest of it will make you rue the choice. btw, I recommend a heat gun for that task, being careful to not soften adjacent gel-coat. The heat gun and a plastic putty knife will make short work of the majority of the varnish removal.

As intimated above, good old traditional spar varnish works quite well. Much better longevity than the urethane synthetics especially when exposed to UV light. Keep the urethane synthetics for below decks use. And the suggestion of the nail-polish bottle is one that Don Casey makes as well in his excellent compendium, Complete Illustrated Sailboat Maintenance Manual. By repairing those nicks and dings immediately you prevent the ingress of water under the adjacent coating and the resultant lifting of the finish. And the fingernail polish bottle means you can touch up without ever having to clean a brush!

I've used a few different varnishes with most of my stuff done with West Marine's Admiral's Varnish, which I just now observe is not listed in their current catalog.

I did a companionway hatch board this winter, which I fabricated out of lowly birch plywood from the Home Marina and marine-ized with westsystem epoxy before coating it with Rust-Oleum spar varnish. My local hardware store sells that spar varnish for the extravagant price of around $5 the quart versus the near $30 I've paid for the Admiral's at WM. I'll report back in time as to the long term durability of my test project and the effectiveness of the cheap Rust-Oleum product.

I know that you're ideally supposed to use a varnish with the highest amount of solids content by percentage. My cheap hardware store Rust-Oleum did not list that data as many priceier brands do. I'm prepared to be disappointed but, for now my stained, epoxied, and varnished hatch board looks phenomenal. I know I'll be touching up the edges that contact the female grooves of the companionway.

My basement steps look great three years on after my wife did them in the Minwax Helmsman Spar Urethane Varnish although I suspect that her use of it was motivated equally by it's slipperyness when wet as much as great appearance. I have noticed a certain rigor on her part in paying the Aflac as well as the life insurance premiums. Coincidence, I think not! (g)

[southerncross31]

I had the same exact thing happen with Bristol Finish! Tiny bubbles form when applied in direct sunlight. It happened several times before i figured out what was causing it. That stuff is also nasty smelling to work with. I also had patches of it flake off. However, the places where it has adhered properly look great and my tiller was in direct sunlight all summer with no signs of trouble! I think the reason i had certain spots that didn't stick was due to the fact that the previous owner had oiled the teak and i didn't prepare it properly. I am going for a second attempt this season so hopefully it will work. Also, some of the woodwork i brought home and did in my barn with a small porcelain heater drying them on low. These pieces turned out much better and have lasted longer. I also tried applying some to close to sundown and the condensation that formed turned the BF and opaque white color, which looked horrible!

[camaraderie]

Larry/Suzi...good post BUT I have a different view of Cetol Gloss. The purpose of Cetol Gloss over the top of Cetol Natural Teak is so that you don't have to keep adding layers of COLORING to your teak coating. This prevents buildup and eventual ugliness. The Cetol gloss (unlike varnish) does not lift and separate but rather WEARS and may be touched up without sanding ...and redone entirely with the only prep being a scotchguard pad.
As you rightly point out...Cetol and Cetol Gloss don't look as good as Varnish...but it is close enough for me and a hell of a lot easier to maintain. I agree with you entirely on Bristol Finish...loots as good as anything when you put it on (properly) but is a major mess to deal with down the road.

[pigslo]

The bubbles are outgassing from the wood due to heat from the sun.
pigslo

[brak]

I figured this multi-layer Cetol applicatin method a while ago (because I have no patience for varnish and sanding) - and it seems to hold up really well - I would get good protection on teak for years.

Didn't know Cetol Gloss was a top layer cover for Cetol - guess thats why when I used it once directly on wood it worked so poorly Same with Cetol Light - it's neither here nor there. But I will definitely try Cetol Gloss the next time i need to add a coat to the toerail.

As far as color goes - I am sure tastes differ, but personally I love the color of Cetol - it is nice, rich and looks good to me.