how to rip binding strips from celluloid sheet stock

**Dave Richard** · Feb-20-2021, 1:44pm

I'm repairing a '27 Stahl/Regal mandolin for a customer, which required removing the back. I'll need to replace the black celluloid binding. I have some .060" thick sheet stock on hand, and am wondering how to best rip .090" wide strips off the sheet stock. I have a tablesaw and bandsaw, but not at all clear on how to accomplish this. Anyone with experience and can advise me?

**billhay4** · Feb-20-2021, 2:27pm

I don't think the tablesaw will work, Dave, due to heat buildup. I'd suggest a bandsaw with a very fine blade. I'd make them too wide so I could smooth them with sandpaper and I'd smooth one edge between each cut.
This is an amateur's take on this problem. Others will have more insight.
Bill

**Richard500** · Feb-20-2021, 4:54pm

Dave, real celluloid?
If so, be careful with a saw as it can ignite. Frank Ford cuts (thinner) stock by either scribing and breaking, or scissors. A bench shear might be the way to get uniform strips at 0.090”. Warming might be useful.
If you’re not sure if it is nitrocellulose, break off a little (very little!) piece and put a match to it. On a non-combustible surface.

**sunburst** · Feb-20-2021, 5:18pm

Originally Posted by Richard500

...A bench shear might be the way to get uniform strips at 0.090”...

Yep, that would be ideal, and from the looks of strips that I have seen that's how they were cut. Nearly no waste and no flammable dust
When I worked "at the factory" we bought celluloid binding material in large sheets and cut our own strips using a bandsaw with a fence. We cleaned up the rough edges on a belt sander. Yes those processes leave flammable waste in the form of dust, but we only had a fire once. One of the guys was sanding something made of steel on the belt sander without cleaning up all the celluloid dust first. Sparks + celluloid dust = fire!

**Richard500** · Feb-20-2021, 5:51pm

I’m a particularly slipshod worker in general, and have made the bandsaw (cut wood then ferrous metal) mistake many times without ignition, but I know it’s common, as is the ignition of dust in exhaust plumbing from static sparks. I can testify from personal experience that if you’re wearing a welding helmet, sometimes it’s not easy to notice that one’s clothing, seating, or nearby things are actually burning.

**Greg Mirken** · Feb-20-2021, 6:01pm

I use a strip cutter from MicroMark, their number 14568. It uses x-acto blades, and has a micrometer type screw to set the width of strip. I set the blade so it makes a deep score in the binding sheet and snap the strip off. I’d attach a link but I don’t seem to be able to get their website to cooperate at the moment.

**Kevin Knippa** · Feb-20-2021, 6:12pm

https://www.micromark.com/Wood-Strip-Cutter

**Dave Richard** · Feb-20-2021, 8:02pm

Thank you all. I quickly learned, here and elsewhere, it's a matter of cutting or shearing, not sawing(which I suspected). Yes, real celluloid. I may try the Micromark mini-cutter, but turns out, a local friend does it with a sheet metal shear, and has offered to cut some strips for me.

**j. condino** · Feb-23-2021, 1:00am

If it is solid black celluloid, nobody will be able to tell the difference under finish if you just use black ebony or some similar substitute; unless you tell them, then they will obsess over it!

**HoGo** · Feb-23-2021, 3:35am

I've used saw I made by filing teeth into thin bladed knife with curved edge (working on the pull stroke). Or you can just buy veneer saw which is perfect for the job. No fire risk (sweep the floor) and less material waste.
Few times when I needed to rip one 1/4" wide IBW strip into two small strips for "side bound" Loar style mandolin headstock I used sharp pointy knife (don't use the thin floppy exacto blades but good utility knfe works) and good straightedge. Start with one precise cut and then gradually deepen it (don't use too much pressure or blade will wander). If you are careful the blade will follow the first cut. Do this on the other side and work till they meet in the center. 5 or 6 passes on each side will cut it cleanly.

**Richard500** · Feb-23-2021, 10:01am

I suggested (metal working) shears because that’s what I have, and have used on plastics, wood, other stuff. In particular, a fairly standard device called a Beverly shear is handy for curved cuts. Got me thinking, though, about using a pizza-cutter wheel on semi-soft materials. I’ll give it a try if I ever get back to the shop. And of course, the more recent paper cutters that replaced the knife-type also use a small sharp wheel for linear cuts.

**MikeEdgerton** · Feb-23-2021, 10:52am

Originally Posted by Greg Mirken

I use a strip cutter from MicroMark, their number 14568. It uses x-acto blades, and has a micrometer type screw to set the width of strip. I set the blade so it makes a deep score in the binding sheet and snap the strip off. I’d attach a link but I don’t seem to be able to get their website to cooperate at the moment.

That's a great site and the tool is great as well.

**Dave Richard** · Feb-23-2021, 11:20am

Originally Posted by j. condino

If it is solid black celluloid, nobody will be able to tell the difference under finish if you just use black ebony or some similar substitute; unless you tell them, then they will obsess over it!

I did think a black fiber material would also work fine. But since I have the black celluloid, and frequently use other colors of celluloid for binding replacement, I really want to setup, to be able to cut narrow strips as needed, for future repairs.