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Gluing Formica onto a disk

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swittetsakee:
I'm going to paste a few Formica into alt-bearing disk edges.  Because there are not any obvious start-stop areas on a disc, I'd like to have both Formica ends butt together cleanly.  The strips are cut a little longer than needed at the moment.  Is there a favorite way to get them to line up as tightly as you can?  I plan to use contact cement to adhere the Formica.
If I dry fit to a tight joint, then paste, I guess the change in circumference due to this glue-line will open the gap greater than you would expect.  If my math is right, the gap could be glue-line thickness*2pi, or about 6x the glue-line.  That's not insignificant.  The problem is I do not have a means to correctly ascertain glue line thickness beforehand.

If I paste bits with overlapping ends, then trim (an approach that I'm leaning toward), there is the risk that the cut will likely be slightly off.  And exactly what to cut it with?  A knife will require multiple moves and will have to be guided correctly.

Any words of wisdom before I put down the adhesive?

Ryan Fletcher:
Overlap now, trim to fit later.

Marvin Alexander:
Do you have a small block plane?
Leave as small an overlap as you can and glue on except for the last 2" or so. Plane the loose end until it fits then glue down. Remember if using contact glue it can be reactivated with heat and the laminate can be stretched slightly if heated and repressed to take up a small gap.
When gluing with contact, too dry is better than too wet especially on a curved surface. Too wet and the laminate will try to lift. Too dry, just apply heat and repress.
On tight curves the laminate (especially the ends) can be pre-bent with heat. Use a scrap pieceto test how much heat it can stand before blistering. It's a surprising amount. It can get a lot hotter than you can bear to hold. Heat it then bend to a tighter curve than required and let cool then glue. It'll be less likely to try to lift.

Lastly, although it will be more visible, when placing the bearing put the join in a position where it won't ride over one of the Teflon pads.

Dave

PS: I usually cut narrow strips with side cutters before using the block plane,

wordpuzzlesubc:
Tin snips (sheet metal scissors) will also cut laminate, here too its best to cut the waste off in thin strips, and test-try beforehand. Most snips leave one side basically straight, and curl the other as they cut. Be sure the curl is the scrap side.

Waka Belcher:
Hi Dave,

where did you get your laminate from? Ready to do the alt bearings for my 33" dob. Used to get it from Scopestuff, but they are out of stock. My bearings 1" wide on 23" radius semicircles.

Best regards

Stephen.(45deg.S.)

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