Replies

1. 
   peter28 | Dec 30, 2007 07:18pm | #1

   Hi Doug,

   First off, sorry for the delay in getting back to you.

   What type of wood are you finishing?

   It's quite possible your brushing technique is the culprit.

   You can thin the product if you wish. It could help the flow out characteristics of the coating.

   You need to sand in between coats with 220 or 320 to help level the surface and give it tooth for the next coat. This will also sand out the little bubbles you are seeing. Be sure and clean all the dust off the surface prior to re-coating.

   If your last coat has any surface defects there are a couple of things you can do.

   If the final coat has little "nibs" in it; that is it is not as smooth to the touch as you'd like you can use the back of your sandpaper to burnish it down. That's right , the back of the paper.

   The coat needs to be dry to the touch but not cured yet (18-24 hours). With the back of the paper, rub the surface down. You'll notice the surface will smooth out and have a nice feel. Use moderate to light pressure when doing this.

   You can also use a very fine wetdry paper like 600 or 800 grit. If you use them to wet sand be sure the coating has sat for a couple of weeks (at least) to cure up. Be careful as it can cut through edges quickly.

   Follow that with some 0000 steel wool. When I get done using steel wool I'll clean all the dust off and then buff it vigorously with a dry cloth like a tee shirt. This will give you a soft feel and glow.

   This is just one way to rub out a surface. Let me know how you do.

   Peter

    

    

    

    

    

    

1. 
   Pangolin | Dec 31, 2007 09:10pm | #2

   Thanks for your response, this is what I've done since my initial mail.

   The wood is red maple.  I got it from a friend about 2 years ago, as it blew down in a wind storm.  I've rough milled it and let it dry for 18 months.  Moved it to my shop (garage) for a couple weeks and then milled it.   The project I was making was an outdoor bench.  The top was natural edge slab from the tree, flat sawn, smoothed with a power planer and sanded to a smooth finish with an orbital sander to 220.  The base was dimentional wood 2"x3".

   What I noticed was that the bubbles appeared to be raised and broken through and they were a gelatinous.  So almost like a clump of the finish.  That got me thinking to when I stirred it up that the bottom of the can had 3/8" of thick 'jelly' and maybe that got suspended in the finish and dried hard, so somehow I didn't mix it well enough. 

   So I resanded down to bare wood.  I added 15% thinner and tried again.  This seemed to go on much better, without thinning it was very thick.  But those clumps where still there but not as often.   When I sanded out those clumps to get a smooth finish what I noticed when I applied the next coat of finish was that you could see the little hole and the sanding marks; I was using 220.  So if I ended up with 3 coats of finish you could see 2 layers of sanded out clumps and sanding marks.  The finish didn't adhere or cover those very well.

   This was a Christmas present so I just let the second attempt at what it was; not very good; looks great far away but not smooth to the touch and imperfections under the top coat from the previous sandings.

   What I noticed was that the milled lumber (the bench support) had far less of a problem then the slab of wood used for the bench top.  I don't know if that because it had less surface area and so it was the same (number of clumps per inch of service).  So I don't know if finishing changes when you do a slab of wood versus dimmentional milled lumber.

   Right now the bench is with my father-in-law, curing in his house.  I'd love to know my options for fixing this - whether that's how you outlined in your response or if I should start over again or start a new project :-). 

   I've read the article by Sean Clarke on a durable external finsih (http://www.taunton.com/finewoodworking/SkillsAndTechniques/SkillsAndTechniquesPDF.aspx?id=24929) but was unable to find the resources needed in time so went with the Minwax.   If you have other recommendations for outdoor finish, please let me know. 

   Thanks again for your time and your response (it's very helpful).

    

   -Doug

1. 
   peter28 | Jan 02, 2008 04:44pm | #3

   Doug,

   There are times when I just bite the bullet and start over. It happens to all of us. Those pinholes will be problematic the rest of the way. I think starting over would be your best bet.

   Your basic cure is simple; a paint filter. You can pick them up at any good paint shop. The Jelly you are finding in the bottom of the can is the "flatting" agent that is added to create a "satin" coating. If not fully incorporated and filtered it can be a problem as you have found out. 

   Thin out your finish to your touch and then pour it through the filter into a clean container. Tilt the container when you pour the varnish in so not to introduce bubbles into it (the same way you would pour a beer to minimize the head)

   If you want a clear coat for outside I would suggest you used a marine varnish of better quality.

   Some of the top brands would include Interlux, Petit to name a couple. There is also McCloskeys. You'll find these to be superior to the minwax brand.

   If you look at the positive side of things, you just climbed another rung on the finishing ladder. It is a learning process that takes time and practice.

   Good luck.

   Peter

    

    

1. 
   Pangolin | Jan 02, 2008 10:47pm | #4

   Perfect.  Thanks for your response.  I don't mind learning on the job and doing it again as long as there is hope for a better result, which is what I have now.   Thanks again for providing such a great service.

   Doug