Cutting plywood on bandsaw without splintering.

[Bkn]

I know a table saw would be ideal for this and I do have plans to get one but I could do with being able to do it on the bandsaw for now.

Does anyone have any tips for keeping both cut edges clean for straight cuts in birch plywood? I can get away with putting something in place that will restrict the fence movement because every single cut I need to make is the same size.

I have a 6 tpi blade in the saw at the mo and I've set it up as best I can. However I notice if I stop a cut or pause half way through a cut the blade kind of cuts the spot it's in slightly wider than it would if it was moving. Anyone have any thoughts on this also?

Thanks

 

[jimi43]

Sounds like it's wobbling laterally in situ so you could try seeing if the guides are set correctly top and bottom and ensure the top guide is as low as possible to clear the thickness of the ply but no more.

A zero clearance insert is also worth making...take out the old insert and make an MDF one and then using the blade that's in it...cut the slot to fit it. That way the kerf of the blade is perfectly matched with the insert. Make sure you change this regularly.

Jim

 

[joiner_sim]

Or, if you don't like Jim's idea, I'd make a board to go on top of the machine bed.

 

[wcndave]

Sounds like you got two different problems. 1 is the break out on the bottom side, which with plywood can be a lot. the zero clearance insert will make this much better. Or you can put a board underneath what you're cutting, to "back it up". That board of course will slowly get cut away, OR if you are doing the same size, you can just leave it there, perhaps even clamped.

however your standstill hole widening will mean this backboard will get progressively worse, so either keep moving it along, or set up your BS better. could however be a kink in your blade...

I rarely use a bandsaw to cut a straight edge, a router can do this for you much better if you have limited space and no table saw.

 

[Oryxdesign]

Sounds like you got two different problems. 1 is the break out on the bottom side, which with plywood can be a lot. the zero clearance insert will make this much better. Or you can put a board underneath what you're cutting, to "back it up". That board of course will slowly get cut away, OR if you are doing the same size, you can just leave it there, perhaps even clamped.

however your standstill hole widening will mean this backboard will get progressively worse, so either keep moving it along, or set up your BS better. could however be a kink in your blade...

I rarely use a bandsaw to cut a straight edge, a router can do this for you much better if you have limited space and no table saw.

Or a circular saw on a rail.

 

[wcndave]

Sounds like you got two different problems. 1 is the break out on the bottom side, which with plywood can be a lot. the zero clearance insert will make this much better. Or you can put a board underneath what you're cutting, to "back it up". That board of course will slowly get cut away, OR if you are doing the same size, you can just leave it there, perhaps even clamped.

however your standstill hole widening will mean this backboard will get progressively worse, so either keep moving it along, or set up your BS better. could however be a kink in your blade...

I rarely use a bandsaw to cut a straight edge, a router can do this for you much better if you have limited space and no table saw.

Or a circular saw on a rail.

if you have a rail :wink:

 

[Oryxdesign]

Sounds like you got two different problems. 1 is the break out on the bottom side, which with plywood can be a lot. the zero clearance insert will make this much better. Or you can put a board underneath what you're cutting, to "back it up". That board of course will slowly get cut away, OR if you are doing the same size, you can just leave it there, perhaps even clamped.

however your standstill hole widening will mean this backboard will get progressively worse, so either keep moving it along, or set up your BS better. could however be a kink in your blade...

I rarely use a bandsaw to cut a straight edge, a router can do this for you much better if you have limited space and no table saw.

Or a circular saw on a rail.

if you have a rail :wink:

Make one, thin piece of mdf a bit wider than your saw, screw a straight edge to it trim off with the saw. If you search on here you'll see some nice ones.

 

[wcndave]

but how do you make the straight edge? until you have made the rail.... there's a hole in my bucket....

anyway, i use one of those powertrack rails and they do work nicely for that. many ways that i think are better than bandsaw, and sometimes better than tablesaw for bigger panels.

however the OP was concerned about breakout, and CS would certainly do that in most cases, unless you have a festool or something that has a special device to prevent it. however if i had that money and no TS, i know what i would buy

 

[Bkn]

Thanks for the tips

I'd absent mindedly been cutting the thin sheets on the ply with the guide far too high - lowered it right down and no more sideways wobble.

I'll give the board on top of the table a go as making a ZCI will be a pain.

The router table idea - brilliant. I hadn't even thought of that. Gave it a go and it makes nice perfect edges. Much slower than the bandsaw though.

I have a makeshift rail for my circular saw and it does decent enough edges and I'll be using that to cut boards down to more manageable sizes but I need to cut lots of 130mm squares so the other suggestions are more suited.

 

[wcndave]

ah, for the router i was actually thinking the same as the circ saw, ie a straight edge on a board, chop off in one pass, then clamp that on your line and cut. benefit over CS is that you get no breakout as you are not cutting down through the wood. downside is that it's a bit time consuming, but for clean ready to go edges you can't beat it!

for 130mm squares, go for making a zero clearance "top" to your bandsaw table, or always cut with something underneath.... far the easiest way..

can't even think how you did that with router table, unless you have a nice mitre which holds the piece without moving, as using a fence would require you to already have a straight edge....

 

[jimi43]

ZCI may be a "pain" but they are the most valuable pain you can add to your bandsaw...trust me on that one.

Make a load at one time and then just replace them as and when you need to. The moment you do circular cuts you will need to replace them anyway.

I guarantee that the one that comes with it would have more clearance than an MI5 agent with a Blue Peter badge!

:wink:

Jim