Replies

1. 
   Robbie | May 10, 2004 04:08pm | #1

   Joejoe:  Without seeing the piece of wood, it is hard to say.  If you believe that seasonal movement would not be an issue, then go for it.

   West Systems epoxy has worked many times for me and I believe they have both black and white color additives for their epoxy system.  I've used the white successfully, but have not seen the black before and thus cannot provide an experienced endorsement.

   Note that epoxy will breakdown over time in the presence of direct UV light exposure.  Something to think about depending on where this piece will be displayed.

   BW

2. 
   UncleDunc | May 10, 2004 04:23pm | #2

   I've done it with oak, on a smaller scale. Mine was a piece of oak 1x4 from a pallet. It had one burled edge with voids and bark inclusions. I ended up chipping most of the bark out because the wood was very dark right under they bark anyway, so removing the bark didn't change the look very much. I was afraid if I left the bark on, the epoxy might stick to the bark OK, but I wasn't sure how well the bark would stick to the wood.

   I tinted the epoxy with sanding dust instead of pigment. I had tested some epoxy with oil based pigment earlier and it never got hard. It wasn't sticky, but it was more flexible than I liked. I think I used wenge to color the epoxy, and it has held up for five or six years now. The only problem I had was mixing the epoxy without bubbles. I had to go back and patch it in several places. Actually, that wasn't too bad, because I never got exactly the same color on any two batches, so the mottled patches made the epoxy look more organic. I've been thinking about rigging up a vacuum pump for vacuum clamp veneering, and if I do, I'll also come up with some kind of small bell jar so I can suck the bubbles out of epoxy.

   I wouldn't hesitate to cut dovetails in a drawer front with an epoxied crack in it. Just make sure the sides of the crack are well wetted with epoxy before you fill it. Gentle heat (blow dryer) can help with that. And take it easy when you cut the joints.

   Another thought that just occurred to me is that you might route out a cavity in the back of the drawer front and glue in a patch of sound wood to back up the crack. Leave just an eighth or quarter of an inch thickness on the front to show the crack. Maybe make the patch the same depth as your dovetails. (I'm assuming since you're using a decorative piece of wood for the drawer fronts that you're planning on half blind dovetails.)

1. 
   joejoe | May 10, 2004 08:36pm | #3

   Robbie and Uncle Dunc,

   thanks for the encouragement. I really like the idea of an oak patch on the inside of the drawer to help support the epoxy patch!

   The dovetails will indeed be half blind. Now to see if anyone local carries the West System....

1. 
   RonInOttawa | May 10, 2004 10:31pm | #4

   You could also find either coloured epoxy (usually black) or tints from most golf club component suppliers. I've included a link to one company below. If you need more, please ask and I'll give you a batch of links.

   Regards,

   Ron

   http://www.golfworks.com/index.asp?bhcd2=1084217135

2. 
   Robbie | May 10, 2004 10:55pm | #6

   JoeJoe:

   You can order West Systems epoxy from hundreds of places.  A for sure is to go to WestMarine.com and they will have it there.  The WestMarine and West Systems are not affiliated, although they share the "West" in their names.

   I also like the idea of the piece of oak for a patch.  But use it for aesthetic reasons, not for structural or support reasons.  A thick patch of cured epoxy is much stronger than the wood patch - it just doesn't look as nice.

2. 
   EdHarrow | May 10, 2004 10:53pm | #5

   I'm not a chemist, but being ignorant never seems to get in my way, LOL.  Re belljar and epoxy I have two concerns, one of which I'd ask an epoxy source about - the effect of pulling a vacuum on liquid epoxy; what would outgas, what would the effect of the outgassing be, and would it have an impact on my vacuum pump. 

   A belljar looks pretty harmless, but the picture changes PDQ if one implodes and doesn't have appropriate safeguards in place.  There are small ones available from Edmund Scientific that are poly carb, not glass, and safer in that respect.  I've used them without a containment device, but I'd never use a glass one in that manner.

1. 
   UncleDunc | May 10, 2004 11:29pm | #7

   >> ... the effect of pulling a vacuum on liquid epoxy; what would outgas ...

   My understanding is that curing epoxy is not a matter of solvent evaporation. Generally the only outgassing you would get is the air bubbles that were stirred into the mix. So, no vital components removed from the epoxy, and no harmful vapors going into the pump.

   A Google search for the terms

   epoxy bubbles vacuum

   turned up 1690 hits. Of course not all of them were about vacuum degassing, but many were. The second one on the list was from an epoxy vendor.

   >> A belljar looks pretty harmless ...

   Good caution. I've never seen one fail. Is it pretty spectacular? What are the appropriate safeguards? Once you have an idea how long it takes to get the bubbles out, I suppose you could use a metal bell instead of glass or plastic.

2. 
   OneofmanyBobs | May 11, 2004 12:38pm | #9

   Do not use the polycarbonate bell jars with solvents.  I had the baseplate fail on one.  Very loud bang but a minimum of flying pieces.  Glass bell jars are perfectly safe.  Should have a wire or perforated metal shield, but they're not anything to worry about.  Use a very big cup for vacuum degassing.  The epoxy can expand to 5 or 10 times original volume when it foams up.  There's more air in there than you might think.

3. 
   bill_1010 | May 11, 2004 02:49am | #8

   Pick up some microballoons when you get your epoxy.  They are tiny glass beads whose purpose is for gap filling.  This saves your epoxy and builds volume.   If you cant find it at your epoxy dealer, auto body shops also have microballoon additives. 

   Along with carbon black or other black tint you can stabilize the crack