Cutting thin wood

[thawkins57]

I did a QUICK search and didn't find the answer to my question, so I'm sorry if this has been asked and answered...

I'm going to cut my first portrait out of 1/8" walnut.  I know I should stack it with something to avoid breakage in the thin areas, but my question is this:  Should I just stack it on top of a heavier, say 1/4", piece of inexpensive plywood?  Should I sandwich it between two pieces of, say 1/8", plywood?  Does the sandwich material need to be quality or can I use a luan or similar plywood?  I want to avoid any breakage as much as possible. 

Thanks for all your help - as a newbie, I've gained a wealth of information here...

Tim

[GrayBeard]

OK...what I do when cutting portraits is the following.

Take a minimum of three layers, and place the "prime" one in the middle of the stack.
I use 1/8" BB plywood for the 'extra' pieces in the stack simply because I use FD New Spiral #2/0 blades and do not want any voids in the wood so the blade cuts true and doesn't drag or jump while cutting.
The faces are sanded to 220 grit and the backs at least to 150.
Clamp the edges, one at a time, overhanging the edge of the table and tape the edges with Blue 'delicate' painter's tape so they are well secured.
Spray glue the pattern and apply to the face of the stack. Be sure you rub it down well so it adheres during the whole process.
Then I apply clear 'good' quality packing tape to the face covering the whole pattern and once again rub it down well.

As I am cutting I will drill about 25 or 30 pilot holes at a time and lightly sand the back side to get rid of any 'breakout' from the drill and this also keeps the back side fairly smooth.
When the portrait is done I then sand the back side very well with the 220 to eliminate as many of the 'fuzzies' as possible.

Separate the stack pieces and sand lightly.

Then carefully remove the tape and pattern from the top piece and almost always this is a good portrait as well as the "prime" one from the center of the stack.
Usually the 'bottom' piece is usable as well. Another bonus.

Then I clean up any remaining 'fuzzies' with my set of needle files and an Xacto knife.
Dip the pieces in BLO mix and spray with Satin lacquer.

Now you are ready to mount to the backing of your choice.

You have probably seen that I cut around the outer edges of a of some of my portraits and mount them on black felt backers. That final cut is made by lightly drawing a light pencil guideline around the picture and then cutting carefully with a FD Polar #3 blade.

That 's how I do it....it is not the only way I am sure but this method has served me well.

~~~GrayBeard~~~

[dgman]

Hey Tim, When I stack cut 1/8 material, I usually stack three or four layers of the same material. That way you can choose the best of the stack. If you don't want to use good material for the whole stack, put your best piece in the middle. You can use any quality of wood. I find that  a 1/2" stack works best for me.
With that said, I have not had any unusable pieces so far!
Damn GB, You always beat me to the punch!

[GrayBeard]

I think I am going to copy that post and save it on my desk top so I don't have to write it all over again the next time! Also the one I just put up about the spiral blades!

Sorry Dan...was just taking a coffee/donut break and jumped in.

Back to cleaning shop and houe, Company Coming!

~~~GB~~~

[tux_linux]

GB and Dan are right.

For me left to say: it depends on my Zero-inlay in the saw table. With a good, new inlay I have no breakouts on the bottom layer and can sell that one too, with a worn out inlay I'm hardly able to sell the top layers.

So you should consider to change that small thingy before cutting something special.

[thawkins57]

Thanks for your replies... I think I'll go pick up some 1/4" plywood and sandwich it... I only NEED one, but a second one would be nice.  It's a portrait of my girlfriend and her dad... I can give one to him and one to her. I'll let you know how it turns out.
. 
Tim

[GrayBeard]

Tim...as I look at your pattern the only place I see that might give you a little bit of trouble will be the 'pupils' of the eyes...everything else looks fairly straightforward.

Take your time and follow the directions and you should be fine.

And always remember that a little 'mistake' disappears after the paper pattern is removed. Only you know it was there and you can forget it!

~~~GB~~~

[KarlB]

I will also chime in to say be sure blade is 90 degrees to the table.  This is especially important when stack cutting with intricate detail.  What looks good in cutting on top may be cutting right into other lines on the lowest piece. 

My blade was out just a small bit when I stack cut three 1/4" pieces and a waste board and ruined the two on the bottom!

I will also say it's better to stack cut thin plywood even if all you want is one copy.  It's easier to cut (the blade slows down) and someone will always like what you've done and want one! 

Karl

[mrsn]

GB gave excellent advise!

Since Karl noted that the blade should be 90 degrees I will also mention that it helps to make sure that the drill bit is also 90 degrees. I messed up a project once because my holes were not quite straight and the spacing cut into adjcent spots.

[GrayBeard]

In my defense I ASSUME everyone keeps their table and blade square and also their drill but I should not ASSUME!

Good catch guys! Will add that to my instructions!

~~~GB~~~

[Russ C]

Don't worry GB, you can't remember everything. 

[GrayBeard]

I was in the newbie shoes not so very long ago and now tend to forget what I have learned in such a short time among my friends here.

As we get further into any hobby or actually any endeavor we tend to do certain things automatically and forget to include them when passing on help to others.

I remember trying to teach a rather well endowed lady friend to swing a golf club..."Honey you must swing over them or under them you cannot have a good swing by trying to swing THROUGH them!" She just turned 75 and still laughs every time she picks up a club!

~~~GB~~~

[thawkins57]

I was in the newbie shoes not so very long ago and now tend to forget what I have learned in such a short time among my friends here.

As we get further into any hobby or actually any endeavor we tend to do certain things automatically and forget to include them when passing on help to others.

I remember trying to teach a rather well endowed lady friend to swing a golf club..."Honey you must swing over them or under them you cannot have a good swing by trying to swing THROUGH them!" She just turned 75 and still laughs every time she picks up a club!

~~~GB~~~

There IS a lot to learn... I read and read and read, and when I start cutting, I forget most of it until it's too late.  I DO appreciate everyone's comments and suggestions.  It's just like anything else... practice practice practice.

[dgman]

Hey Tim, Just remember this, Try everything, and use what works for you. As a scroll saw instructor I tell my students This works for me, It may not work for you. It is just a suggestion, do what works for you.