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Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by David Mary, May 15, 2020.
I cut a bunch of scales out just before I replace my bandsaw blade.
I was a hair away from picking up some 36-40 grit AOs with my last belt order, for this purpose. I'm having minor issues with the scratches from my 60 grit belts though, so I chickened out..
One belt that I did pick up though, was the yellow Klingspor LS312. They work very very well. They cut better and longer than the normal brown AO. For this knife I roughed out shapes with 80 grit, then to 180 before hand sanding. Since then I got them in 400 as well, eager to try and abolish some more hand sanding..
I have no problem with shaping micarta on my belt grinder, I was only referring to when I cut it with my angle grinder. I have to bring the wheel into and out of contact, or keep it moving back and forth, because constant contact and pressure makes it burn and smoke. I can't turn the speed of my angle grinder down. On my belt grinder, for shaping, I use whatever coarse belts no longer cut metal fast enough, and then clean up with a worn 220 grit ceramic belt before hand sanding.
Yes, to the first question, and I don't know to the second, because I don't use them wet. I have a well ventilated shop and wear a respirator, so a little flying G10 dust is nothing the shop vac can't get later.
Well I try ............ Just little smoke and light burn......worse become as thickness increase..........lengthwise cut better . I don't like it , for short cut is OK for long cut no it can be dengerous. I found that cutting disk for stainless last longer for cutting carbon steel ........
Micarta is very different from G10 , maybe you side load cutting disk and from there come temp. and smoke ?
Micarta definitely burns easier than G10. Maybe it's because the laminating layers are canvas, linen, or paper, none of which deal with heat very well compared to fiber glass. As far as cutting it goes, does no one else use a bi metal blade on a metal cutting bandsaw? It doesn't seem to dull mine.
I use 36 and 50 grit AO and Zirconium mix belts and have never had a problem burning Micarta. I remember a thread a while back that talked about (I think this is the terminology) open and closed grit belts. Closed like ceramic works best on metal and open like AO is better for wood. I think the open belts are better for Micarta as well.
Willie why not use the diamond blade on the tile saw?
I had my first experience with Micarta, i'll see if I can post some photos.
What. A. Fucking. Mess. It's from a pretty reputable seller on I.G, but I think I noticed something. This material and G-10 (the issues i've had with it) are from overheating. I'm pretty sure I did the same to both. I used way overnuked belts on the material during shape and just mash it into the belt til it's the right shape, but it's burning I think.
Not burning visually but melting it to a point it ruins the integrity of the material. The micarta developed fibers that WOULDN'T sand away, and I used a razor blade to cut them away. Even then, it wouldn't sand right - it was changed, gummy, and i've scrapped it. Man, was it going to look good too...
I'll work it much slower, with fresher belts, but I thought because I wasn't actually burning it that the heat wasn't effecting it - it is. You can tell.
Fresh A/O belts. Same as you'd use for hard to sand woods. I run maybe 1100 sfpm tops belt speed.
We cut large quantities of G10 & micarta every week. Here are a few things we've learned:
1) Cut and/or grind both materials as slow as possible.
2) Cut and/or grind wet when possible.
3) High carbon, bi-metal, carbide and diamond will all cut both materials if the speed is slow. Go too fast and the blade will be ruined.
4) All angle grinders are too fast.
5) Do not confuse the working characteristics of factory made material with home-made material. If you think material made with a wood die and hand pump hydraulic jack is the same as material made on a 300 ton press with steam heated platens, you are mistaken.
This is a very important point. There is just no way comparing them and I am never getting "home made" stuff again.
I cut scales on both the bandsaw and mitre saw. I use the mitre saw when I want a perfectly straight or angled line, for example when making multi part handles. But that saw is 6300 rpm with a 216 mm blade.. It gets the job done and is faster than the band saw (18 tpi bi metal) but it sure is a little hot and the dust is all over even with the vaccum connected. It's like starting a jet engine.
I want to update my mitre saw anyway and was looking around and found that Festool has a variable speed (1300-3500 rpm) one, and also has a 64 teeth speciality blade for "hard and fibre-reinforced plastics". Saw has a little over 12" capacity. That may be something for cutting G10 and micarta sheets and scales, dust collection also looks better than on my current Dewalt (but still, dust collection is never GREAT on mitre saws..).Just a thought on the topic.
Micarta just sucks to grind. It's like Willy says, try sanding your jeans. Canvas, linens, paper they're not stiff enough to support the tool pressure required to grind compared to the fiberglass in G10. Ask any boat builder. It's not dissimilar to how a blade edge forms a burr.
I bought a full sheet of canvas Norplex micarta years ago and I only use it when requested because I just hate working with it.
G10 on the other hand, I love working with.
If you're using micarta use sharp belts at low speed. Even better, rough it out with a router flush cut bit and corner rounding bit.
I bought four 12x12 sheets, 3/8 thick, before I knew better . Norplex.
But allthough I don't like working micarta as much as G10, I still think it feels better on a handle in some ways.
So I'll use them I'm sure.
I haven't found linen Micarta to be all that hard to finish. I'm not fond of black canvas though.
It cuts really slowly and burns. I think the grit is too fine.
I never thought of the router. That’s a great ideas! Thanks!
Festool is nice, but pricy. If you can afford it, go for it.
Yes Festool is in a league of their own. I got their plunge cut track saw a few years back when I had to build some fitted furniture. It's a joy to work with, the build quality and precision make it kind of hard to look back..