Replies

1. 
   RalphBarker | Oct 07, 2012 09:18pm | #1

   Methods, methods

   I think I'd try the drill out method first, as that is most likely to be the cleanest. Or, one might use a Romulan precision disruptor, but they are difficult to find.  ;-)

1. 
   kenackr | Oct 07, 2012 09:39pm | #2

   Ralph,

   The precision disrupter was, of course, my first thought; however mine seems to have gone missing. The Romulans really don't like it when one gets away from them. They probably beamed down one night and grabbed the one I took when they abducted me the first time.

   After I posted, I then thought perhaps a reamer on the top head might be a solution. Ream until the head separates from the shaft and no harm done because I'm going to replace the plywood anyhow. So I stop when I hit wood and that should do it. I'm warming up to that approach.

   Ken

2. 
   roc | Oct 07, 2012 09:58pm | #3

   Disrupters are great but the dilithium crystals come at a cost

    Hi,

   I had to cut a rivet the other day and was glad I finally got smart enough to stop trying to drill them out.  The bit garbs  the rivet and spins it just when it seems you are getting some where.  Still not enough metal gone to punch it out.

   I was cutting a steel rivet so I just used an abrasive wheel grinding bit.

   For your aluminum that won't work.  The aluminum just smears across the abrasive and loads it up and it won't cut.  Try one of these or three

   http://www.amazon.com/Champion-Cutting-SD2-Carbide-Diameter/dp/B004GJXX0A/ref=sr_1_7?s=hi&ie=UTF8&qid=1349658890&sr=1-7&keywords=ball+bur

   Yes that price is too high !  You won't need a carbide bit just go to the local welding shop or hardware (not Ace they are too high as well ) and get bits made from High Speed steel HSS.

   Don't push so hard they grab and race off the rivit just hard enought to cut the aluminum.  If you find they are not aluminum then grind them.

   If you have a small drill that turns fast that would be ideal or better yet a die grinder because you can hold it closer to the cutter.  The idea is to cut across the top of the rivet not straight down into it so it does not start to spin.  In fact you could drill part way until it does spin and then use the ball bur to cut the rest until you can knock it through with a punch.

   I couldn't even find a link to my Porter Cable 1/4 inch drill.  It turns at three thousand rpm.  Most 1/4 inch drills are way slower.  I bought it for turning drill bits 1/8 inch or less in steel and was lucky to find it.

   You might find a used die grinder at the local pawn or used tool shop for not much.  Handy to have around.  I find the Dremels too gutless and the chuck too small for work this big.  Also it is quite possible to over heat and burn up the Dremel doing this scale of work and that is way more than a used die grinder.

   PS: thanks for all the detale in your question it is a great help.

   PPS: reamer will spin the rivit.  You won't hit wood until the whole mess gets hot enough to catch fire.  Ha Ha Ha.

1. 
   kenackr | Oct 08, 2012 10:18am | #4

   Roc,

   Yes, I understand better now from your experience. Because a bur has smaller cutters it will be less likely to grab.

   I have both cutoff wheels for aluminum and burs in my dremel kit. I'll give those a try & let you know what happens.

   Ken

3. 
   HowardAcheson | Oct 08, 2012 03:30pm | #5

   I have owned a number of boats and worked in a boatyard.  Most often, we would just drill the head off the rivit using a bit one size larger than the hole size.  Just took a couple of seconds.  If the rivit didn't fall out, we would just punch driver.

1. 
   kenackr | Oct 08, 2012 04:34pm | #8

   Howie,

   That's pretty much what I have done in the past for other pop rivets. I guess there's no harm in trying it first to see if the rivet is going to spin like happend with Roc. I can always use  one of the backup methods if that fails.

   Ken

1. 
   roc | Oct 09, 2012 01:02am | #9

   I must confess

   Nearly all of my rivet excavation has been limited to metal to metal or metal to plastic joints and fairly small rivets.  Sounds like the larger heads in wood get a better grip.

   The reason the burs don't turn the rivets, if you find you need to go to that extreme, is not that the bur has smaller teeth but that the force is across the rivet head and not radially on the axis of the rivet.

   If your cut off wheels look like brown abrasive don't bother using them on aluminum.  If they are silver / metal discs with diamond grit you may have a chance because they may not smear the aluminum and load up and stop cutting but in any case both types of these cut off discs are for cutting very hard metal or other materials that are too hard to file or use the burs on.

4. 
   Westchester | Oct 08, 2012 03:46pm | #6

   Splinters

   Can you laminate a new 1/4 in. plywood board over the 1/2 in. deck ?

   SA

1. 
   kenackr | Oct 08, 2012 04:33pm | #7

   SA,

   The answer, in this case, is no because I waited too long and the top has delaminated to the point where it is by no means a smooth surface that would lay flat for a good bond. One other factor too, the scaffold deck is manually raised & lowered to adjust height. More weight would make that process tougher than it already is. But it's a good thought!

   I bought Pressure Treated 1/2" that I'm going to put a sealer on, hopefully to slow the delamination process down. If that doesn't work out too well, I'll get marine grade plywood next time.

   Ken