Jig Saw cutting help

[lrrowe]

I started to ask a question in another OP post and I did not want to hijack his thread. So I am starting this one.

Here is a quoted question I asked there:
Anyone: Anyone: what am I doing wrong with my jig saw? While it may not be an issue with these side walls, when I cut most thicker boards or plywood, my blade curves and I do not get a straight cut looking down. I have used new blades with the same problem. I am using a good model Dewalt jig saw.[color=#FF0000][/color]

See: viewtopic.php?f=42&t=32504&start=60

[ajpat3]

Just a thought, and I'm no pro, I find that my jigsaw has a sweet spot. Too fast a cut, and I get deflection. As soon as I start getting impatient and start to bear down on my saw, I get bad cuts. That said, I've never made a cut like your doing. Good luck.
Arthur

[dales133]

As above it depends on a few things.
My saw isn't a super expensive brand but it's the top of the range black n decker.
Blade selection is pretty critical to match the material.also never force the blade as it's far more prone to wandering.
If your saw dosn't have a decent bearing guide behind the blade your going to struggle anyway

[lrrowe]

Thanks for both ypur responses. I will keep an eye on my speed and see about the blade bearing mechanism. When I get to a store, I will look for new top of the line blades.

[desertmoose]

Bob:

A non-plumb cut with a saber/ hand held jig saw mostly comes from trying to keep the cut on the line by pushing the saw sideways. This bends the blade away from vertical.

It's easy to say, and hard to do, but the correct way to guide a cut is to turn the saw and ALWAYS push the blade straight into the work.

Heavier blades, and roller guides can help a bit in keeping the blade vertical, but even then, a side push will result in a non-plumb cut.

Practice helps.... except by the time you are done practicing, you are done with the project...


Sam

[KCStudly]

So to further that thought, if you do stray away from your line (on the waste side, of course ) I find that it is better to move the blade back and try to skim the line again, moving very slowly into the cut, to establish the correct track again.

Doesn't always make a bad situation better, but it avoids the tendency to push sideways.

[lrrowe]

I will keep both these suggestions in mind the next time I cut. Maybe tomorrow evening I will experiment (after I get new blades).


Now I will ask another question. If my cut to the side of my CT for my window will be through both the aluminum (.030 thick) and 3/8 in plywood, is it best to select the blade for what is best for the aluminum alone? Or is there another choice I should consider?

[dales133]

You can get blades that are multi purpose but a fine blade should easily do both.
I'd recommend you cut from the aluminium side though

[lrrowe]

Thanks...I was going to do that...outside in.

[ctstaas]

A couple of thoughts. Use a hand saw to start the cut and once the power saw is in the kerf go slow. Many times I have use a sacrificial piece as a starting guide. Again once the cut is started go slow enough to stay on line.
Enjoy, chris

[lrrowe]

I went to Lowe's yesterday and bought the longer Bosch blades. They appear a little thicker. If I am able, I will try them today using the advice posted here. Thanks all.

[jonw]

I've found using good blades are the key. A nice stiff and sharp blade will cut like butter. Just be sure to switch blades once it starts going dull.

The ones I like best are thicker and have teeth along both outer edges of the blade. I stay away from the cheap, stamped Sears and Vermont American ones...

[lrrowe]

Jonw,
I have my fingers crossed.

[Corwin C]

A master craftsman taught me that the proper pressure on a jig saw is to visualize what you would be able to apply with one finger on the very back of the saw. Turn the saw to follow the line just like you would if you were using "one finger." The trick here is to hold the saw properly and apply just that pressure. It does take practice. The person who taught me this could intentionally cut a straight line on the bottom and a wavy one on the top (I still haven't figured that one out.) And another thing ... many jig saw/blade combinations do not cut "straight", rather the saw will travel crabbed slightly to one side or the other.

[lrrowe]

Thanks Corwin,
I have not tried my new saw blades yet and I will employ the "soft touch" approach. I do know that my past efforts put a lot of pressure on the saw. So maybe there is hope for me.