Replies

1. 
   scooter1 | Aug 01, 2003 06:54pm | #1

   Use a backer board against the fence.

   Regards,

   Boris

   "Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934

1. 
   Justus | Aug 01, 2003 07:11pm | #3

   No, he is already using a backerboard.

    You might be right about not holding it tight enough. You could try small hand clamps, the mechical advantage and the fact that the clamps don't get tired is a big help.

    You could also gang up the pieces together, with a clamp, each one acting as a backer board for the next,

    And finally if you are still getting tearout, lightly score the cut line across the grain with a razor, the line will then be sanded out when you make the joints flush. Justus Koshiol

   Running Pug Construction

1. 
   scooter1 | Aug 01, 2003 07:54pm | #4

   I re-read his post and I didn't see that he was using a backboard against the fence--only a fence. And, he says the fence dado and his finger joint dado match up. Of course they do.

   He needs to get a piece of scrap and place it behind the piece for dadoing. AND, move the scrap, along with the piece, so that fresh backboard is behind the piece for each new cut. The last poster correctly stated that the backerboard must be tight.

   That blowout is caused by the fact that "the fence dado and his finger joint dado match up."

   There should be no blow out if a backerboard is used, and if there is, I would be astonished. This like using a backerboard for planing a door, on the exit side of the cut--it will always chip out, unless one has some scrap.

   Regards,

   Boris

   "Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934

2. 
   forestgirl | Aug 01, 2003 07:11pm | #2

   If you cut the slot in the fence with exactly the same dado thickness that you're using for the box joints, you should not be getting tearout.  Is there any chance that one of the dado blades is in backwards? (Don't laugh, lots of us have been there!)

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

3. 
   firemarshalmike | Aug 02, 2003 04:05am | #5

   Would it be safe to ####ume that the thickness of the backer is not all that important?

   For instance, could I use luan? It's cheap! BTW, I like the idea of ganging up the pieces. I'm trying to get more efficient. I will try it with two pieces clamped together next time I make a batch of these cabinets. Actually, I'll try it on some scrap material first.

1. 
   Justus | Aug 03, 2003 10:21am | #6

   no the thickness isn't that important, I'll often grab a piece of 1/4 ply and place that behind the workpiece, then just slide it down a notch to keep a fresh surface behind the cut.

    Just as a side note, unless your not covering these boxes and you want the joints visible for effect, you might want to think about biscuts. I think it would save half the time needed to set up the finger joints, cut, then sand flush.  I've also made boxes with four corner miters, with 3/4 stock there is no need for reinforcement.

   Just a thought.  Justus Koshiol

   Running Pug Construction

1. 
   firemarshalmike | Aug 03, 2003 02:24pm | #7

   The exterior of these  amp cabinets will probably not be covered. I'm going to have to spend a little time repairing them. Some folks want them covered in tolex, some want the wood exposed. Fortunately the the tearout isn't to bad. I don't think the repairs will be noticable to the untrained eye. It's just going to kill more time. These are going to become hand built tube amps. They need to look great. I don't want this to happen again! This is my first project for sale (part time hobby supporting venture at present). I want my customer to come back for more cabinets. I imagine folks who can make these are a dime a dozen.

1. 
   Justus | Aug 04, 2003 12:20am | #8

   good luck, I wish you well in your venture. Justus Koshiol

   Running Pug Construction