Cleaning the brush: A Chemical Engineer's perspective

This post appeared originally on Windborne In Puget Sound

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Good varnishing brushes are definitely not cheap! The quickest way to ruin one is to let varnish dry in the brush - not something any of us wants to do.

But cleaning a brush is not an easy task. You may think that after triple-rinsing it in fresh paint thinner, the brush is clean. But put it away for a couple of days, and when you go to use it next, the bristles are  disappointingly stiff.

As a Chemical Engineer, I learned several things that have made brush cleaning a lot easier.  (What?  Practical knowledge?  Who knew?):

• Use a counter-current wash system. This keeps the clean end of the system separate from the contaminated end. In a real chemical plant (for example, an alumina refinery) there would be as many as 10 stages or more. Here we will make it simple - we'll use only two.  Do it like this:
  
  
  
  • Save an empty paint thinner container. When you rinse out your brush, dump the now-contaminated solvent into this container. Soon you will have lots in there. As soon as you have enough, this is now your stage 1 rinse.  Squeeze out all the varnish you can from the brush, and then clean it thoroughly in the stage 1 rinse solution. Squeeze out all the stage 1 rinse, and wipe the brush on a rag, trying to absorb as much of the stage 1 rinse as possible. Dump the stage 1 rinse back into the stage 1 container.
  • Next, rinse the brush in 3 small changes of clean solvent. As above, drain all the now contaminated fresh solvent into the stage 1 rinse container, wiping the brush nearly dry between rinses.
  This works because even tho the stage 1 rinse is not pure solvent, it is not very far from it, as compared to the varnish itself. Then the pure solvent is only used to rinse out the stage 1 solvent - not raw varnish. There is a secondary effect: some of the varnish (and paint, and stain, and...) precipitates out in the stage 1 rinse container. When it does so, the stage 1 rinse liquid becomes less contaminated. By doing things this way, your use of fresh solvent will go down considerably, even while your brush gets cleaner.
• Exclude one of the reactants, and a chemical reaction will stop.  Curing paint or varnish is a chemical reaction between the resins in the varnish and the oxygen in the air (and water vapor, if there are urethane resins involved).  Exclude air, and the reactions stop.  This is why varnish does not cure in the can.
• Reaction rates roughly double with every 10° rise in temperature. For our purposes here, the converse is the more valuable: reactions rates are halved for every 10° drop in temperature.

Putting these things to work, on a day when I just need to preserve the brush for tomorrow, I give it a quick but thorough rinse in the stage 1 solvent, getting most of the varnish out of the brush, and then wipe it mostly dry on a rag.

Next, I tightly wrap the brush in aluminum foil - this excludes air and water vapor.

Finally, I store the brush on top of one of the holding plates in our freezer.

I really have no idea how long this process will preserve a brush, but I can set a lower limit.  I have pulled a brush out of the freezer (I forgot it was in there) after a month, and it was still pliable, ready to use.

A floor for the locker

Please welcome new contributor s/v C'est la Vie!  In this project posting from June 12, 2010, Jeff shows us how he installed a floor in one of the cockpit lockers on C'est la Vie, improving stowage and protecting a pump at the same time:

With the paint dried and the wiring installed, we turned our focus back to the cockpit lockers.  We decided to leave the port side locker as is, but add a "floor" to the starboard side locker.  Below is an image of the locker...

The black hose on left attaches to our secondary, large capacity bilge pump.  The pump visible in the lower left of the frame is our primary, small capacity bilge pump.  The bilge on our Morgan is very inaccessible so placing the filter and pump mid-line in this hatch allows the filter to be cleaned and the pump to be serviced easily. Typically in this locker we place winch handles, snatch blocks, boom vang, etc. in milk crates.  The milk crates inevitably slide down an rest against the pump & filter.  Hence the desire for a floor.  In the image above I have already added nail strips along the forward bulkhead and the midships bulkhead (these are the white strips and made from seateak.)

Cardboard was used to create a template for the floor...

Once the fit was correct the cardboard template was transfered to 1/2 marine plywood and the  floor was rough cut.  I added a hatch in the center to provide access to the filter and the bilge pump.  Below are all the pieces of the assembly...

As of this evening the pieces were assembled and the non-visible side of the floor was finished with 3 coats of epoxy...

Since this project will not be exposed to sunlight/UV we simply used west epoxy with the fast cure hardener.  This allowed us to glue up the assembly and get a few coats of finish on in a matter of hours.  Most epoxy is not UV stable so projects or parts that will be exposed to consistent sunlight must be finished with an appropriate product (i.e. varnish or Bristol Finish).  Tomorrow we will complete this project by applying 3 to 4 coats of epoxy to the topside of the floor.

... and here is the completed project:

Looks really nice, doesn't it?

Pledge drive

I continue to be amazed with the attention this blog is gathering - thank you for making this the 6,862,142^th most popular site on the entire Internet!

But I can't keep it going forever without your help.  There just aren't that many things on Eolian that are bloggable.  For this to work out for all of us, everybody needs to contribute - think of this as a pot luck dock party.

Come on now.  All of you have a small project of one kind or another that others would be interested in seeing. Contribute to the feast:

• Write it up and send it to SmallBoatProjects at gmail dot com

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• If you have already written it up on a blog somewhere and are willing to share, tell me where in the wide world of the Internet to find it , and I'll come and get it.

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• Give me permission to "mine" your blog for projects. Anybody who is writing a blog about boating has numerous small projects buried in there. I'll ferret them out, if you let me. No, I won't put your content on here without your permission.

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• Send me what you have, and I'll do the write-up, with full credit going to you as your project, of course.

Every posting will feature a link to your article (if there is one) and a link to your blog (if you have one).  In addition, all contributors will permanently have a link in the "Contributors" box on the right side of the blog. This ought to drive some of the traffic that this site is seeing back to your site.  I will not take any recent posts (unless you tell me otherwise) - that way this site will not be in competition with yours. Instead, it will hopefully serve to "reactivate" some of your older posts.

But the most important benefit you'll get is the warm feeling of having helped someone thru a problem - one that you have solved. And we will all be the richer for it.

Pitch in!

The little Dutch boy could have used this...

Mike and Rebecca on s/v Katana have this up on their blog. This stuff looks like magic!  I know that there was at least one occasion on Eolian when having some of this onboard would have been a good thing (but that's a story for another time).

After hearing some strong recommendations for the product and watching the video below, we decided to invest in a medium-sized tub of Stay Afloat. The product, which is billed as an “Instant Water Leak Plug & Sealant,” is pretty cheap when compared to a sunk boat. We’ve had it onboard for a while this season and have yet to use it, which if definitely a good thing!

If anyone out there has any experience with this stuff, please post a comment!

Two birds, one stone

Where this reading lamp had been mounted, directly to the cabin wall, moisture from the failed window directly above had stained the vinyl headliner material.  The window had long since been replaced, but the stain remained.  I made a small teak plaque and mounted it over the stain, and then mounted the lite to it.  The end result?  The stain is no longer visible, and, the installation looks a lot classier.

Vented loop vent

That sounds kind of recursive, doesn't it? Vented Loop Vent.

But given what it is that the vented loop on your heads is venting, it's probably a really good idea.  On Eolian, the original vented loop fittings were cast bronze, and were fitted with a tiny version of the joker valve on the vent fitting.  That is, the flaps of the duck bill would allow air to enter the top of the vented loop, but would prevent contents (or content vapors) from exiting.

In an Ideal World, that is.

But here in the real world, the occasional  puff, or drop would escape.  And you know, it doesn't take much.

So, I installed the smallest size thru hulls I could find at Doc Freeman's (a famous rabbit warren of a chandler here in Seattle, sadly now gone) into the insides of the bulwarks, and hooked up the vents to them with clear plastic tubing.

This truly is one of those very small projects that makes a big difference in the livability of your boat - especially if the head is near your berth.