Plywood splintering

[Dagon]

Any hints for reducing splinters when using a drill and jigsaw on marine ply? I'm using Hydrotek BS 1088 mahogany for a Bolger Cartopper and although I'm getting nice, clean cuts with my bandsaw, tablesaw and skill saw, even with a fine blade I've had some pretty nasty splinters when I use the jigsaw. Also when I drill holes for inserting the jigsaw blade to start a cut. Is this a technique issue or a tool issue?

[ 06-27-2002, 08:23 PM: Message edited by: Dagon ]

[Mike Vogdes]

Its allways helpfull to score your cut with a razor knife first, befor using your jig saw. When you do cut with the saw be carefull to cut to the score line.

[On Vacation]

In drilling, back up your plywood with a solid surface underneath of the area being drilled. In jigsawing, use a wide tape like masking tape on the area you are cutting and then draw the line on it for a cleaner cut. The worse is cutting cross grain.

[Don Maurer]

Some jigsaws have a control for the amount of forward motion the blade has. The greater the forward motion, the more splintering. If you have this control, set it for the least forward motion. Use a sharp blade with lots of small teeth. Keep your cuts slow.

[FParth]

What oyster said. This is the best way to keep plywood from splintering.

Also, a jigsaw cuts on the upstroke, so use a fine blade and put the best side down. I never run a jigsaw right to the cutting line. I'll get close and then use a plane or sand down to the line.

If you're using a drill bit that has a center point, drill just far enough that the point exits the other side, than drill from that side.

[ 06-27-2002, 11:56 PM: Message edited by: FParth ]

[John B]

I'd add that there's blades and there's blades.
eg. I use T144d blades in my bosch which I wouldn't call fine by any means. good multi purpose blade. Each alternate tooth cuts one side and is kerfed out slightly so you get a bit of a scribing action from it.
Your "fine" blade might be too fine for the job and be carrying material with it ,causing the breakout.

[Kristian]

Use brad-point or forstener drill bits. If you can't get these then a good trick with spade bits is to drill 3/4 through the plywood or until the centre pointpokes through, then stop and drill from the opposite side using the centre hole as a guide.

[Ron Williamson]

All that,and see if you can find blades that have been machined instead of stamped.Generally they are shiny and the teeth aren't set.Instead,the blade is milled so it is wider at the front than at the back.I use Makita #10 blades for this kind of stuff and countertop laminates.Some laminate blades have teeth milled so that the lower ones cut on the up stroke and the upper ones cut on the downstroke.
R

[Dave R]

The jigsaw blade tips already given are good. How about making a simple upgrade to your jigsaw, too? Cut a piece of tempered hardboard (Masonite) to fit on the sole of the jigsaw. Cut a slit in from one end so it will just fit around the jigsaw blade. Stick this thing to the bottom of your saw with some carpet tape and you have a zero-clearance plate. This works essentially like the backer when you're drilling through the plywood (or other wood, for that matter) to support the wood next to the cut.

This trick also works well on circular saws, too but you can simply stick the masonite on the plate and do a plunge cut through it.

If you are concerned about not being able to see where you're cutting, cut out a V at the front of your plate so you can see your line. Just make sure the blade runs in the slot in the base plate.

[Dagon]

Thanks for the excellent advice. A couple more things I figured out last night were to make sure to lock my saw at the highest speed and keep my forward motion slow and deliberate -faster cuts cause more splinters.