Cleaning Brushes

[Dan]

I have dirt in the varnish :-(
I used my brand new Badger Brush and strained the varnish.
I applied some varnish with foam brushes a few weeks ago. This coat was sanded with 320 grit and wiped clean. I decided it is time to switch to the new brush for the final few coats.
I cleaned the new brushes with soap and water and then with mineral spirits a few times.
The first coat with my new brush was beautiful. I cleaned the brush three times using mineral spirits, then washed it out with acetone twice and then washed it in the sink using dish detergent twice and spun it several times. Placed it in a plastic bag.
Next coat of varnish has dirt or specs of some kind of debris in it. It came from the brush, I think. The parts, the handrails and the companionway sliding top rails are sitting on the piano, on temporary feet, in the back room. There is very little air moving in that room.
What is the best way to clean the brush to ensure that there is little to no dried material left in the brush to come out and haunt me?

[Tim]

I think most varnish brush nuts would say that the brush should be stored with the bristles suspended in kerosene, or similar, with the brush well above the bottom of the container. This would prevent anything inside the brush from ever drying out. It's next to impossible to get every last bit of gunk out of the bristles.

Then, the brush can be cleaned just before use each time in mineral spirits.

Or so I have read. I still have good luck with foam brushes for my varnish, though there's little doubt that a clean, high quality varnish brush would be better.

That said, are you sure it's dust and particles in your varnish, and not tiny air bubbles that pop on the surface? That's also a common afliction with varnish, usually in colder weather.

[Dan]

After looking at the finish very carefully, it is small air bubbles that did not pop. The pieces are in the house so temperature should not be a factor.
Maybe I just need to thin the varnish just a little more.
I changed to Badger brushes because the foam brushes left too many air bubbles.
I'll keep trying.
Dan

[Tim]

Sometimes using too much thinner is actually the culprit with those air bubbles. Keep experimenting. In general, you want the least amount of thinner in your varnish as you can, while still allowing acceptable flow. The better the brush, the better the flow, all other things being equal, so you might be able to use less thinner. Other than the first few coats on new wood, there's no requirement for thinner--and it's better if you can use none. (With Epifanes in particular, it's difficult to spread without at least a dash of thinner, but other varnishes spread more easily.)

The tiny air bubbles, even if they remain in the "final" finish, tend to disappear to the eye. While they may seem glaring and unacceptable to you now, you'll probably find that subtle imperfections will not be a huge problem when the job is more or less complete.

Putting a bright (ha!) spin on things: at least each of these coats, if less than perfect, is providing you with a deeper and thicker base for your final finish. Only the last coat need be good enough for your eye. All previous coats, of course, get sanded and covered.

And remember that there's no such thing as a final coat of varnish. Since it always will require recoating at some point in the future, you only have to live with the last coat for a few months or so before you sand it and try again.

[guest(shep)]

Well it's hard to improve on Tim's posts, both in content and style. So, a couple of comments:
-Use thinner in the sealing coats only. These would be the first 2 or 3, typically, depending on the wood and the conditions . Since you are inside , the conditions should be ideal - say 70 deg f and 40 % rh.
-depending on which coat you are on , 220 grit or 320 grit will take care of your air bubbles , no problem. Another coat without bubbles and you will never know they were there.
-there are lots of different ideas and methods out there developed over a long time about how to do this stuff. Read up some and you will find what works for you. Rebecca Whitman's two books are an excellent place to start.
- Last but not least, don't be super critical of your work. I have come to like the "character" that some imperfections provide. If you continue to varnish over the years you will get lots of practice- as Tim says : there is NO final coat!
- Good Luck and keep at it . It's worth the effort.

[Dan]

I have Rebecca?s book and have read it many times as well as other articles.
One problem I was running into with sanding between coats was sanding through every coat so every coat ended up being the first coat in some spots.
Two weeks ago I sanded the varnish with 320 and then had to leave town for a while.
When I returned, I applied three thinned coats in one day without sanding between coats. One early, one mid day and one late. More bubbles with each coat. I will sand it with 320 and try an un-thinned coat this time and see how it works. I'm sure it will come out better.
I do hear you loud and clear about some imperfections and character. I am my worst critic. As we all are that do this sort of stuff.
A very good friend used to say, " Just trim a little off of your perfectionism and get the job done!"

Thanks everyone,
Dan

[Tim]

Three coats of varnish in one day? That's too much, at least with any typical solvent-based varnish. Varnish cures by outgassing the solvents contained within. It needs time to allow this process to complete of its own volition. The more thinner you add, the more solvent there is in the varnish. The air pockets you see are the result of this outgassing.

Buildup that is too thick may not completely cure beneath, though it might cure on the surface; eventually, the uncured varnish contracts, and leads to the ugly wrinkled and alligatored look that you see sometimes. One coat per 24 hours is the max (again: at least with typical varnishes).

Sanding between coats need only be quite light; you shouldn't be trying to sand out all small imperfections for a perfectly smooth surface, at least not at the price of the finish thickness. You should never go through to bare wood during your sanding, except in rare cases (hopefully rare, anyway) where you need to sand out big drips or runs.

The key to building up a deep varnish shine is to get many coats on, not worrying overly about how perfect they are. Light sandings between each coat are necessary, but only to scuff the surface. I normally use 220 between coats, though 320 is fine.

Then, after 6-7 coats (depending), if you want to flatten the surface, you can sand pretty throughly with 220 paper (or sometimes even something more coarse, like 150) to completely flatten the surface. With this many coats already built up, you will of course remove some of the varnish, but won't go through to bare wood anywhere; you'll probably end up with at least a net of 3 coats, and a perfectly flat surface.

Then, after this step, each subsequent coat you apply will be very smooth and glossy, and you can build up another 3+ coats to your heart's content--again, sanding lightly between coats. If you should get a major flaw (a run, for example), then you should sand it out before recoating. Only in these last few coats does brush selection and technique really begin to matter. (That said, you don't want to be sloppy in the initial coats--but nor should you worry too much.)

Regardless of all the information you read (including mine), the key is to find the process that works successfully for you, and your own individual needs. One technique does not fit all. Keep experimenting, and you'll get it down. You can always sand it out and start again with a new coat (even though this can be irritating when you're hoping to have that last coat down...)

Varnish is a labor of love. It is time consuming, frustrating, and sometimes difficult. It doesn't hold up well in sunlight, and requires constant recoating and lots of love and attention. For a perfectionist, there could hardly be a worst job, as it's so supremely difficult to get an absolutely perfect coat. Yet it's all worth it in the end; nothing looks like nicely-varnished wood. It makes all the difference between a basic boat and one that people will take a second look at as they pass by.

And, interestingly enough, it's enough of a black art that most people's first comment will be about your brightwork, even if the brightwork represents a tiny portion of whatever overall project you might have done. It's probably the most outwardly visible sign of a well-cared for boat, and is the thing people notice.

(Off-subject rumination: most of the sweat, blood, and tears that go into a boat restoration project will forever remain unknown to the casual observer. They'll see the pretty varnish, and might, if you're lucky, comment on the paint job, but they'll never see--or comprehend if they did see--all the important stuff beneath the surface. Appreciation for those aspects is reserved for a select few who might have done something comparable sometime.)

[dasein668]

More on sanding:

From the Q and A section of the Epifanes website

Runs make us happy. At least we know the varnisher is getting good mil thickness. We would rather see runs than holidays. Unless the sags are excessive, most imperfections can be dealt with prior to the last couple of coats. If extreme, deal with them individually at the time.

[Dan]

And the sad part is I knew better. I'm not in any rush so I don't know what I was thinking.
I will take the heat gun to it and remove all the varnish that is on there now and start over. The varnish is soft and will never harden.
Good thing is that there is not a lot to strip. I am only working on 5 pieces, all of the pieces are in the house.
The boat isn't even going to see water in 05 so I have plenty of time for each coat to cure hard and lots of time to practice sanding.
I know I am sanding too much and that is what I am having trouble getting the handle on. Practice, practice, practice.
Thanks everyone,
Dan

[Figment]

...I decided it is time to switch to the new brush for the final few coats.
I cleaned the brush three times using mineral spirits, then washed it out with acetone twice and then washed it in the sink using dish detergent twice and spun it several times.

Unless your varnish can calls for it, I'd skip the acetone. Using the wrong solvent for the job can cause things to clump together and bind instead of dissolve and release. Just the mineral spirits alone should be fine.

This I learned the hard way: Don't change from foam brushes to "good" brushes in the middle of the job. If you've learned to get good results with a foam brush, stick with it. Varnish flows differently (not necessarily better or worse, just differently) from a natural-bristle brush, and there's a learning curve involved, just as there was when you first got started with foam brushes. Lots of great varnish jobs have been done with foam brushes.

Under the right weather conditions, I can lay two coats a day, but certainly not three. (using an unthinned urethane product, not a true oil varnish) Also, I don't sand between coats, I just rub down with a scotchbrite pad. After the fourth coat or so, I'll shave down any runs with a razor blade, and resume. I only bother to sand things smooth prior to the "final" coat.
I've come to realize that I get very good results with this. I may not have the best brightwork on the river, but I'm certainly in the top ten, and that ten includes boats that are professionally maintained by one of the better-reputed wooden boat yards around.

Tim's right, it's a bit of a "black art". I'm convinced that there is no one Miracle Method, no matter how many books have been published on the topic. We each must tinker around until we find what works for ourselves.

Oh, and I almost forgot to add... CETOL IS FOR GIRLS!!!!! ;p

[dasein668]

Oh, and I almost forgot to add... CETOL IS FOR GIRLS!!!!! ;p

Hey, my wife wouldn't touch the stuff! She's done her fair share of varnish work on our boat... probably does better than me.

[Tim]

I have some other thoughts on Cetol that don't belong on a "clean" forum!

That said, I respect a boater's choice to use the products they like, even if I don't happen to like them. So I'll refrain from Cetol bashing.