Jigsaw setting chipboard alight ...

[HeathRobinson]

Hi, (newbie alert)

Not quite as dramatic as the title suggests, however I did see a few embers fly out at which point my brain worked out that the burning smell must be the wood and I switched off. I'm only trying to make a shooting board out of scrap chipboard, not start a BBQ. I don't have a table saw because I basically work among the sofa's in the living room at present which I hope explains away what I'm doing using a jigsaw to cut straight lines.

I'm using a little 'shed' branded jigsaw with bosch blades that claim to be designed specifically for chip board and soft wood. One is now quite badly blackened from the experience.

What is going on? With this same chipboard I experienced what can best be described as resistance at random points along the cut last time I cut it. Could it be that this chipboard contains nasty stuff like metals? I notice that despite using a guide that the cut becomes decidedly skew in the vertical plane at around about the point the trouble started.

Think I'll leave this well alone for a while and go and get the shooting board parts cut for me.

Simon

 

[OllyK]

I know nothing, but it sounds like you may be forcing the blade or the gap is closing up on the blade.

Can you get a hand held circular saw, far more robust for this kind of job?

 

[OLD]

Start with a new blade chip bd. kills blades check it runs free in its guide wheel and try different amounts of pendulum action make sure you are not side loading the blade.

 

[tim]

Two things:

1. Yes chipboard can contain bits of metal and other unpleasantt things.

2. Check that you haven't bent the blade or been pushing it too hard.

Cheers

Tim

 

[jasonB]

The blades on cheap jigsaws seldom run true to the base of the machine, if you are running it against a guide, the blade will be trying to go in the opposite direction which will cause binding and the blade to wander.

Just follow the line freehand with a new blade, if the saw has pendulum action then use that as well but I doubt a cheapie will have it. Then again a hardpoint saw will cost the same as a pack of jig saw blades and be easier to use :wink:

Jason

 

[HeathRobinson]

Good morning!

Well I had a go at it with a hard point saw and it works well. Why that didn't that occur to me before I attempted the task I have no idea. I prefer hand tools but am never sure they're going to be any good for the man made boards. I figured that the jigsaw would do a neater job.

After I had cut the board with the hardpoint saw I could see more clearly what was going on earlier and it seems it's exactly what jasonB suggests. The blade is definitely not running true in this jigsaw. I have free handed a straight line and the body of the jigsaw needs to be kept at an angle to the cut line in order to follow the line. The saw in this case was basically working in a different direction to the guide. I was concentrating on keeping the guide up against the edge I wanted to parallel while the jigsaw was moving off the cut line and away from the guide edge. Unfortunately it's not easy to see minor deviations from the cut line when running this particular jigsaw. The problem quickly compounded to the point where the sideways force became too great and the blade got stuck in the wood at a weird angle. I continued to run the saw thinking it was just resistance in the wood but in so doing caused heat to build up enough to scorch the wood and the blade. Doh!

Thanks for suffering through the trials of a newbie with me folks :lol:

Simon

 

[staffie]

Glad to see i'm not the only one who does things like this. Keep up the good work.

 

[woodbloke]

Simon - as others have said and you are finding out, jigsaws have a bit of a mind of their own...I personally don't use them against a guide but would follow a line freehand. I think the biggest part of the learning curve is in using the chipboard. You'll find stones, lumps of iron and all sorts of other debris in it and it's good for only one thing that happens round about early Nov Cutting it with the hardpoint saw is good, but don't try and plane it as you'll need to hone the blade again almost instantly. A better alternative would be to use a bit of mdf for the shooting board - Rob

 

[HeathRobinson]

Hehe. Staffie, you'll understand why I call myself HeathRobinson on here then. Interestingly I'm also an Englishman from S'africa. Perhaps this has something to do with how I work :lol:

Thanks Rob. So you're saying the very idea of using chipboard as the material for a shooting board would have scuppered me from the start in any case I was aware that it couldn't be planed but see that it would have to be planed a teeny bit at first to create a small step where the plane blade protrudes further than the plane's sole.

With all these man made boards I am never very sure of their fondness for being worked in certain ways. I also feel a little cautious when working them as I see they're being sold with warnings to wear dust masks and the like these days due to the chemicals in them. This applies especially as I'm working in the house.

 

[woodbloke]

HR wrote:

So you're saying the very idea of using chipboard as the material for a shooting board would have scuppered me from the start in any case

Simon - chipboard is fit only to be walked on, nothing else IMO and I would stay well away from it. A decent quality mdf would be fine to build the shoot from but would create quite a lot of fine dust, so a decent mask (look for a P2 grade, a P1 is good for keeping out bricks) would be an idea and make sure you hoover up afterwards or Miss Robinson won't be a happy bunny :wink: The little step you mention is cut by the plane blade the first couple of times it's used. Provided the plane is kept level and not tipped, then it will guide itself along the shoot by virtue of the fact that the little bit of the sole below the cutter is moving' along the 'step' - Rob