RE: bulkheads / baffles in secondaries

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Original poster: Daniel Hess <dhess1@xxxxxxxxxx>


I've had good luck cutting plastics using a hollow ground blade in a 
saber saw with variable speed so that I can cut slow. That prevents 
the generation of heat which allows the plastic to fuse back together 
right behind the cut.

I also like to drill a 1/4" hole in the center of the disc, mount it 
in my drill press and then at a slow RPM, use a belt sander to true 
or clean-up the circumference of disk. Most extruded plastic tubes 
rarely have a true inner diameter, (they're always a little out of 
round) so I don't get too hung-up on building a perfect circle disk 
because it just doesn't matter. Then I use a dollop of silicone RTV 
to seal the center hole. Also use RTV to mount the disks inside the secondary.

Daniel



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08/18/2006 11:44 AM
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RE: bulkheads / baffles in secondaries




Original poster: "Mark Dunn" <mdunn@xxxxxxxxxxxx>


Dennis:

There are special blades for plastics/laminates that fit your jig saw.
They require a low speed so cut slow.  They also break easily(my
opinion).  Alternaitvely, I use my radial arm saw with a laminate blade
and rough cut the shape.  Then finish it to size with a belt sander.
You can buy a cheap fabricated table that fixed mounts your belt sander
vertically so you can work the part perpendicular to the sander on the
table.  Allows you to get the part to relatively accurate dimensions
without jumping up to a lathe.

Mark


>Original poster: otmaskin5@xxxxxxx

>Hi Gerry, you mention cutting poly board with a jig saw.  Are you
>referring to polyethylene cutting board?  I've tried using a jig saw
>on acrylic & other plastics, but the heat from the blade seems to
>melt the material & the melted material either closes the cut behind
>the blade or leaves a hard to remove pile of melted/refrozen plastic
>along the edge of the cut.  Not sure I've tried polyethylene
>yet.  Any suggestions?  Thanks, Dennis Hopkinton MA