Best method to cut thick balsa without power tools?

[Rktman]

Hi all, need some suggestions on how to cleanly cut through 1/4" and 3/8" hard balsa for a glider build. I don't have power tools and there are some curves and slots involved, and I'd hate to tear up the cut edges with a hacksaw or razor saw.

 

[mcderek]

Use a box cutter and make multiple passes. I'd still use a hacksaw or razor saw though. Leave room with your cuts and sand to final shape.

 

[SkyFire]

Coping saw

 

[Rktman]

Coping saw
View attachment 461752

Won't shred or splinter the balsa?

 

[Funkworks]

I used a coping saw for 1/8" and 1" balsa and it didn't shred or splinter. You never have to apply force. And balsa is so easy to sand just give yourself a margin near the cut line and sand the rest.

 

[teepot]

I would suggest a razor knife, razor saw or coping saw. My razor saw does not tear up the edges.

 

[Steve Shannon]

I would also use a razor saw. Use the finest blade you can get and don’t force it and it won’t dig in.

 

[Daddyisabar]

Old School. A nice thick Xacto knife with a pack of new blades.
Cut the 1/4 inch squishy, cheap balsa into weird shape fins, lable paper and a modicum of CA on the edge. Strong as iron.

 

[jqavins]

This

Coping saw
View attachment 461752

and this

And balsa is so easy to sand just give yourself a margin near the cut line and sand the rest.

and I couldn't agree more.

I would also use a razor saw. Use the finest blade you can get and don’t force it and it won’t dig in.

The coping saw would be much better at curves, I should think.

Hi all, need some suggestions on how to cleanly cut through 1/4" and 3/8" hard balsa for a glider build. I don't have power tools and there are some curves and slots involved, and I'd hate to tear up the cut edges with a hacksaw or razor saw.

If said slots are narrow, you might end up just cutting a kerf and sanding nearly all of it; that would be if there's little to remove in the first place, so don't worry about it. If it's a little wider than that, make two parallel cuts than remove the resulting strip with a knife down at the end.

Another nice thing about a coping saw is that you can even cut holes with it. Remove the blade, make a small hole with a drill, put the blade through then reinstall it in the frame.

(Incidentally, all the same things can be done in soft metals with a jeweler's saw, as that's pretty much the same tool with a finer blade. I have more experience with jewelry work that woodwork with these saws, but enough with wood to know that it's basically the same.)

 

[dr wogz]

The finer the blade, the cleaner the cut. look for 18, 24, or 32 TPI (Teeth per Inch) for fine work / in light material.

as for the box cutter / X-Acto knife route, cut it like you would chop a tree: make a vertical cut on the piece where you want the cut to be, then cut a 'V' groove beside that cut (on the waste side). This allows the blade to pass thru the cut without binding..

 

[icyclops]

Nobody uses an adjustable power scroll/jig saw....dremel even makes a motosaw. Great for cutting curves....
even cut straight then sand....done in no time.

 

[heada]

Nobody uses an adjustable power scroll/jig saw....dremel even makes a motosaw. Great for cutting curves....
even cut straight then sand....done in no time.

I'd use my 5hp 24" bandsaw....but the OP did ask for options without power.

Coping saw, Fret saw, Jeweler's saw, Veneer saw....all with very fine teeth. Back it up with 1/4" foamboard and have zero concern for tear-out.

 

[Rktman]

Thanks for all the great advice guys, I feel a lot more reassured about tackling that build now. I'll cut a little bit outside the lines, especially near those slots and tabs, and will true things up with a sanding block and some emery boards to get those tight corners sharp.

 

[BABAR]

Not sure how it would affect weight, but maybe papering BEFORE cutting might help?

 

[jqavins]

I've long thought that if/when I start papering it would make lots of sense to do that before cutting. Basically, make papered balsa stock and cut from it. Cut multiple pieces from a sheet just like I would with non-papered stock.

 

[Ez2cDave]

Eric,

Take a look at these . . .

https://www.ebay.com/itm/274712385609

https://www.ebay.com/itm/303780044801

Dave F.

 

[heada]

I've long thought that if/when I start papering it would make lots of sense to do that before cutting. Basically, make papered balsa stock and cut from it. Cut multiple pieces from a sheet just like I would with non-papered stock.

I paper after because on some models I want to do tip to tip paper. I get fiberglass-like strength in much less weight and thickness.

 

[Rktman]

Papering before cutting is a great idea, would be a real time-saver. Just glue on the template and cut out all in one operation. Unfortunately it's a tad too heavy for my application, an Edmonds DeeCee Thunder that's already a hefty glider. Now if only there was a way to print that cutting template on tissue stock...

 

[heada]

Papering before cutting is a great idea, would be a real time-saver. Just glue on the template and cut out all in one operation. Unfortunately it's a tad too heavy for my application, an Edmonds DeeCee Thunder that's already a hefty glider. Now if only there was a way to print that cutting template on tissue stock...

Print it on paper, lay the tissue over the print and trace the lines.

 

[icyclops]

Papering before makes little difference than after if you cut with a sharp xacto. but if you are using ply or bass board and intend to cut with a saw blade, it may fray the cut edges and just mean more touch up sanding after primer paint....no biggy.

 

[Rktman]

Print it on paper, lay the tissue over the print and trace the lines.

Hmmm, I've got to try that. I've tried to draw on tissue with a pen before and it tends to stretch and/or tear. Maybe a gel point or some other kind of pen might work better...

 

[Ez2cDave]

Now if only there was a way to print that cutting template on tissue stock...

https://www.stickandtissue.com/forum/cgi-bin/yabb2/YaBB.pl?num=1355532809

http://www.parmodels.com/Printing on tissue/Printing_on_tissue.htm

Dave F.

 

[heada]

Felt tip. Light pressure. Might bleed so watch for that.

 

[mcderek]

Printing on tissue paper isn't difficult. It's common in Free Flight Aeromodelling where weight is important. Check out the links shared above and there are many more if you search online.

 

[BABAR]

Papering before cutting is a great idea, would be a real time-saver. Just glue on the template and cut out all in one operation. Unfortunately it's a tad too heavy for my application, an Edmonds DeeCee Thunder that's already a hefty glider. Now if only there was a way to print that cutting template on tissue stock...

?apply tissue before cutting? Then trace cardstock templates onto the tissues balsa with felt tip marker?

 

[jqavins]

Maybe "trace" the pattern with a tine ball, e.g. the smallest fondant tool or a ball point pen. No ink goes through, but you get a slight indentation in the balsa.