Gemstone Forum archive

Lapidary Shop / Moderator, Catmandewe ( Tony ) => Discs, Wheels, Belts, Pads, and Polishing => Topic started by: James D. Farrow on March 30, 2016, 09:19:10 AM

Title: Using Resin Discs Without Gluing Them Down?
Post by: James D. Farrow on March 30, 2016, 09:19:10 AM
I was planning on ordering a few more backing plates and sponge discs
for my 8000, 14000, and 50000 grit resin soft discs but thought I would run
this idea by you folks here first.

I bought some steel discs (they run from 60 to 3000 grit) that are not
attached to a backing plate. They are thin. You just place them on top
of a backing plate and the washer and bolt hold them down and I have
not had any slippage problems at all. They work fine. You only need one
backing plate to use any steel disc you want.

Now what I want to try on the weekend is to see if I can glue (feathering glue as I hate
the PSA stuff) a sponge disc to a backing plate and then just place a soft resin
disc on top without gluing it to the sponge disc. Hoping that the bolt and washer
will hold it in place without any slippage like it does with the steel discs.

Just not sure if being soft and not rigid like the steel discs this may not work.

Anyone here try this idea before?

Opinions? Suggestions?

Thanks,

James

Title: Re: Using Resin Discs Without Gluing Them Down?
Post by: lithicbeads on March 30, 2016, 10:24:04 AM
If you can bolt through the disc- pad glueing them down is optional in my shop. It would bother the heck out of some folks to use them this way and not bother others at all, you have to decide which camp you are in because you can get used to using non - glued discs and pads. The sic sanding discs can be used in the same way and it is a wonderful way of extending the life of your coarse diamond pads because coarse sic discs cut very quickly when newish and are inexpensive so they are easily replaced. Not having then glued to a backing plate makes the frequent required sic change outs  not a problem at all. When I was carving a lot I would sometimes sand and prepolish certain style grooves by putting on  a thick half inch rubber pad glued to the backing disc and then use a loose diamond pad of a larger size on top of it. This sanding pad draped over the edge of the backing plate and rubber backing and could be used in certain grooves if the speed was maintained at a moderate level. Of course the pads will lie flatter on the machine the faster they are rotating.
Title: Re: Using Resin Discs Without Gluing Them Down?
Post by: James D. Farrow on March 30, 2016, 04:56:49 PM
Thanks for the reply.

Will try it on the weekend.

After I drill the hole through the sponge pad and resin disc.

James
Title: Re: Using Resin Discs Without Gluing Them Down?
Post by: James D. Farrow on March 31, 2016, 03:00:19 PM
Well put the resin disc upside down on a stack of old newspapers
(a piece of wood would work as well), then the sponge pad upside
down on top of that, and finally the backing plate on top of that.

Made sure everything was centered and using a drill, with a half
inch drill bit, drilled through the hole in the backing plate and
into the sponge pad and resin disc. Didn't press to hard. Last thing
you want to do is drill into the kitchen counter. LOL!

Nice clean hole. Worked a lot better than fiddling with an exacto
knife trying to cut clean holes. No end of grief doing that.

Put the backing plate on the Ameritool, and placed the sponge pad
on top and bolted it down. Then lifting up the pad put some feathering
adhesive around all the sides and pressed it down. So far, so good.

Removed the bolt and washer and placed the resin disc on top and
bolted it down. Turned on the lap and spins true. The resin disc lifts
up a bit on the edges but that's because my disc wasn't exactly flat.
No slippage AFAIKS.

Placed it under a couple of phone books and will leave it overnight
to flatten it out a bit.

Looks like it will work fine only having to use one backing plate and
switching out the resin discs as needed.

Will report back if any problems arise.

James







Title: Re: Using Resin Discs Without Gluing Them Down?
Post by: James D. Farrow on April 10, 2016, 04:52:43 AM
O.K. came across one problem.

With the mesh disc not being glued down, if you put a
lot of pressure on it you can have buckling of the disc.
The disc folds up on you and will also stall the motor.

Will try using feathering glue in just a few places around
the disc to see how that works. Hopefully it will stop
the buckling and have the added benefit of, hopefully,
making it easier to remove when it needs replacing.

Will let you know the outcome.

James