FoamStream...

[GPW]

Toaster??? possible ?

Went back with a thick coarse flat rasp and a quick pass down the kerf slots widened them to three times their size , but we quickly found out on a straight slot cut like this , you have to go in and widen the Whole slot , not just at the top ... after a quick vacuum of the slots , the foam is bending much further now ...

[Ned B]

Dunno about your saw, but on mine I can set the depth of cut down to as little as 1/8"... Not just 2 1/2"

[Ned B]

whoops! didn't see that you were cutting that deep (iPhone... pics are tiny there...)

[GPW]

Yeah Ned , it’s that deep (3.5” thick foam ) , but I wish the saw cut was wider , I even re-set the teeth on a jig saw blade to get wider .... it helped a little , bit I still had to go back with the rasp .... and vacuum ...Got the second panel done ... these will be the two side panels that sit above the ones previously installed ... This is where the foam goes from straight (sides) to curved (top) ... Hence the partially kerfed panels ...
The plan is to glue the bottoms of these panels to the top of the other panels already installed , let that dry , and then glue it to the stringers and ribs , with a 10’ board and clamps at the top to hold in the slight curve till the glue dries ... After that we have to start some serious kerfing ...

I realize this is the Grandma method ... so easy , and safe even Grandma could do it ... A router would make quicker work of this ... circular saw too ...

Ps. If I had a spot welder , I could just weld a couple jigsaw blades side by said , save for the mount ...Then I could get a nice wide cut (1/4”) , no going back with a rasp ... May try that as yet ...


Ps. I’m using those blow gun darts as giant straight pins for joining /holding foam .... worked great on #1 Foamie ...

[KCStudly]

Geep, I wonder if you just need to use a longer piece of wire in your hot knife. Wrap the excess around an insulated post (wood dowel). Shorter piece of wire equals less resistance (like a short to ground... blows fuse), whereas a longer piece equals more resistance (heat). Schmaybe.

[KCStudly]

Another thought. Maybe anneal the jigsaw blade so that you can put some twist in it, back and forth every 1/2 inch or so (less than the stroke of the reciprocating action), in effect giving the blade a wider kerf; "wavy set". The foam won't know the difference as far as the annealing goes.

[mezmo]

Is it possible to use a dado blade in a circular saw ?

You could get wider kerfs that way.

http://www.rockler.com/product.cfm?page ... ilter=Dado

BUT, a little Googling on it, gives me the impression that they don't
make them for circular saws and/or most woodworkers don't think
it'd be a good idea and/or-would-be-dangerous to use one in a circular saw.
And it's best or should be mandatory to use at least a fence if not
a jig to dado with it.

Soooo, could you borrow a portable tabletop saw and get a dado saw
blade in that ? And set it up with a groove distance jig too. That'd
probably give you clouds of foam pieces but it could prove faster -
maybe you could hook up some kind of vacuum to the table saw
skirt-bottom to help with that.

Just throwing it at the wall to see if anything sticks...

Cheers,
Norm/mezmo

[GPW]

The big problem is the foam ... it’s 10’long, and I’m doing this by myself ... Table saw is out ... need to use something small and light to move over the material , not vice versa... Actually , the jig saw is doing a pretty good job so far , just not as quick or convenient as the other methods , but doable and not very dangerous ... and now I only have a couple more sections to do , so it won’t be that bad no matter how I do it ... On the other hand , if I was making a few of these , I’d have something much more efficient to do this job ...
Thinking about the hot wire thing .... the depth of the kerf is just too deep for any thin wire ...on 2” foam it might not be a problem ..
But I’m not out of ideas yet ... just need to sleep on it ...

[atahoekid]

Well. GPW, I hope you like the granny method. That's what I ended up doing to two panels and yup it's a mess. Pretty time consuming, very untidy but it works. One thing I did discover is that doing my cuts freehand I could make pretty wide cuts by twisting the circular saw ever so slightly sideways while cutting. It essentially made the blade wider. Don't know how to make your saw do it consistently, but if the width of the cut is important there's gotta be a way to set a jig to fix the angle of the blade from dead ahead to slightly askew.

[Wolffarmer]

To make a circular saw easier to cut at a bit of an angle screw the base of the saw to an auxiliary base made of plywood, at an angle to the edge of the plywood. Then you can run the edge of the plywood along a straight edge that is clamped to the work. Be careful as the blade guard probably will not be working but you sure could get a wider cut, and some what v shaped.

Know what I mean?

Randy

[CampsALot]

You could take an old blade, clamp in a vice and offset every second or third tooth to create a wide kerf.

Warren

[GPW]

Had a couple ideas .... Fiberglass cut off wheel on a circular saw (messy)... or what about a soldering gun ... used as a Hot wire ... ? (Stinky)

[Wolffarmer]

A circular saw at a slight angle would leave a rounded bottom hole with a slight taper. Pretty sure about the taper. I would think a rounded bottom would cause less stress riser than a square bottom grove. At least in metal, not as sure in foam. I think I would at least try a test piece.

Randy

[GPW]

You know Wolf, that may not be a bad idea huh ! I could shim the back of the saw’s bottom plate a little so the blade would present itself at an angle to the cut when using a “guide”/fence... The wider the shim (angle ) the wider the kerf ... Hmmm??? This deserves a test .... Outside ... The foam will be flying !!!

Getting ready to go outside and attach the next panels ...Pics will surely follow ...

[GPW]

OK , that step done , except for not having enough BIG clamps ... had to improvise ...