Jigsaw Troubles

[Dave Warner]

Greetings All:

I'm having some troubles with a Bosch 1590EVSK jigsaw to rip long cuts on both hardwoods and mdf. I don't have a lot of experience using a jigsaw and I'm not sure if the problems are with me or the saw. I would really appreciate some feedback/comments/suggestions regarding the following.

What you see in the first photo is an attempt to rip a length of 3/4 red elm. I'm using a new Bosch T-Shank blade and moving through the wood at a rate of about one inch every 3-4 seconds. After several inches the wood is smoking and the blade is hot to the point of blackening and warping the metal (see second picture). If you look closely at the first picture you can tell the cut line is actually from two cuts. The first, shorter cut, was with a 20TPI blade. When I hit problems with that one I switched to a 10TPI blade. As you can see I didn't have much success with that blade either. The curve in the cut is from the blade warping and deforming (presumably from heat). The base of the saw is tight against the guide during the cut.

This saw has worked fine for cutting soft pine boards, but I've seen similar problems trying to cut lengths of MDF, cherry and maple). A few more notes:
- I'm not engaging the precision guides, as that seems to pinch the blade (my perspective is this would make the problem worse).
- The saw has a blade orbit setting (sets the forward blade angle I think). I'm in position 2 which is supposed to be for most hardwoods. I've tried the other settings and not seen a difference.
- With the blade seated in place there does not appear to be any pinching of the blade. The blade sits back between the guides.


Is this just a newbie mistake?
Could I be moving the saw too fast (though one inch every 3-4 seconds feels pretty slow)?
Is it just wrong to try to use a jigsaw for this function (Don't have a table saw, and don't like ripping narrow boards with the circular saw)?

Maybe the saw is experiencing some problems. I know this model seems to receives favorable comments and feedback. I bought it new in 2006 and have only used it lightly. It has only been this summer where I've started working with hardwoods and started trying to use it in the described manner.

Any thoughts on what could cause this, or how to work around it would be greatly appreciated.

Thanks!
Dave

[Charles Lent]

That's not really the type of cut that you should be making with a saber type saw. It would be better to use a circular saw or a table saw. Your saw is really intended for making curved cuts and doesn't (as you have experienced) do very well when trying to make a straight cut with a guide.

If that is the only saw that you have, try drawing a straight line on the board and then carefully following it with your saw (without the guide). The blades in these saws will seldom cut exactly straight and parallel with the saw's base, which is why it doesn't follow the straight edge very well. If the saw has variable speed, slowing the cutting speed down will help prevent burning the wood and overheating the blade. A blade with more set (teeth bent sideways further) will also reduce the burning, but will likely make a less satisfactory cut. A wider blade (front to back) will tend to cut straighter than a narrow blade, also making it easier to make a straighter cut. Making the saw run slower and slowing your feed rate will do wonders for the quality of the cut. Don't push the saw, let it do the cutting and push it just enough to keep it cutting. I believe that your saw has an orbital function which moves the blade forward while cutting and back for the return stroke. If it has this there will be a lever that adjusts this. More orbital action will likely be better in this case. Less orbital action works better when making tight curves. Carefully following the line by eye and not with a guide will give you a fairly straight (but not perfectly straight) cut. Again, this isn't the right saw for the job.

Charley

[Prashun Patel]

It's going to be hard to get a clean rip line with a jigsaw - even the Bosch (which is probably the best one out there < $200).

MDF and hardwoods are hard on blades. I've never been able to effectively rip with a jigsaw - too much deflection.

You should consider the EZ system if you don't want a tablesaw. It'll allow you to use your circular saw to safely and accurately do what you're trying to do.

Alternatively, you can rip narrow stock by butting your cut edge to a board of the same thickness and then using your circular saw with a clamped straightedge on the waste part of the board to be cut. The butting piece is just there to support the saw foot, so it doesn't need to be clamped. You can also doubleside stick a 'spacer' to the baseplate of the saw to provide the support you need.

[Lee Schierer]

I've made cuts like that with my Bosch jig saw with little problem, though I've never cut red elm. I use the Progressor T-234X blades.

They look agressive, but produce a cut that will rival a cut made on a TS. When ripping you want to use a bit of orbital action on your saw.

[Dave Sweeney]

+1 on the T234X's, great blades.

[John Thompson]

Try Lee's suggestion on the aggressor blades. I've ripped entire sheets of MDF and ply with them. Too many teeth on the two you used. And if the cut is closing behind you it will heat the blade also so stop the saw and wedge the already cut kerf to avoid pinch. I've seen pinch completely stop a circular saw.

Keep the cut slow as the Bosch (I have a barrel grip) practically guides itself.

Sarge..

[Jeff Duncan]

Yup, like the last posts said it's the blades. My Bosch will do whatever cuts I want, I've cut 1/4" plate steel, stainless steel, hardwoods, you name it, it does an excellent job. It can do a whole lot depending on whose using it. When your ripping hardwoods you need to have a very aggressive blade, 20 tooth is much too fine, even 10 teeth per inch is too fine. You should be closer to 5 tooth or even less if you can find it.
Another thing is cut speed, don't go overly slow or you'll just heat up the blade and cause it to dull quicker. It's hard to explain to someone new with the tool, but just put enough force to keep the saw moving forward. You'll find the rate the saw can cut at by feel and keep up that speed.
good luck,
JeffD

[glenn bradley]

+2 on the T234X's. Slow your motor speed as opposed to moving forward slowly with a high speed. This causes a lot of heat and slow strokes don't as much. The Bosch has plenty of power to saw ridiculously slow strokes. I do this on heavily figured wood that want to guide the cut.