Scroll Sawing for Intarsia

by Judy Roberts 10 Comments

Scroll Sawing for Intarsia

If you do not read any further, the most important tip for scroll sawing accurately for Intarsia is CHANGE YOUR BLADES OFTEN. 
If the thought crosses your mind "is the blade getting dull, should I change it?" you should change it. Perhaps subconsciously you realize you are pushing too hard. The cost of the blade is not worth the frustration, not to mention if you have to scrap some expensive wood. 

Check Table Square with BladeTension: Use this link to hear that high "C" note. You do not need to click for the next slide, you will need to click the arrow to start the movie. Sounds of Blade Tension Link. Trouble? Try this one.
Sawing:
  Make sure your blade is cutting square. Check the table/blade to make sure it is square. Next make a test cut, cut a curve then check it with a square. The curve makes it easier to see any light between the square and the cut part.

Cut Hand Size Pieces
Cut the pieces about the size of your hand, this will make it much easier to handle than one large board. After cutting the hand size pieces be sure to turn them over to remove any  tear out with sandpaper. The object to keep the parts as flat as possible to ensure a square cut.
After all the parts have been laid out it is time to start sawing. If you used the same board (color) to layout many parts, start by rough cutting them into smaller more manageable sections.


Start cutting the easiest parts first, like the outside edges
. This lets you get into the swing of things.  Cut some of the outside edges, parts that do not have another part next to it. I like to mark all exterior parts with a highlighter.While sawing, stop often after making a cut and remove any tear-out on the bottom side. While you're at it check your cuts with a square.
 



Plan your cuts: 
Try to make your cuts so the last cut will “drop” the part off the larger block.

Note the extra part added to the left of the eye. The last cut is a short smooth line. Drill any holes before you start sawing, like the hole for the eye.

 

Blade Sizes?


Blade Selection: I like the Platinum Plus blades for hardwoods and the Gold blades for softwoods.
Use a #5 blade for most sawing. If you have more intricate cuts try a #3. If your wood is very hard move up to a #7 or #9 (also try applying clear packing tape on the wood).  

We mainly use the blades with reverse teeth, the blade has around 6 teeth that cut on the “up stroke” and in most cases will help decrease the “tear out” on the bottom side of the part.

After cutting all the exterior lines, use a smaller blade like a #2/0 to a #1 to cut the interior lines (between parts 11 and 10 in the illustration) You loose less wood with the smaller blades. 


Where to Put the Blade?
When cutting a  part it is best to put the center of the blade in the center of the layout line, thus removing all of the line. With more experience the goal is to leave half of the pattern line around the parts. If you are using a larger blade you will need to move the blade a little more to the outside of the line.  

Hand Placement: While scrolling, your hands are in control of the part. The blade is in control of the sawing. You will find that by positioning and repositioning your hands as the need arises you will be in control of your wood. Always remember to have at least one hand holding the wood down firmly on the table at all times.
Your hands will be in motion, always setting up for the next curve or turn on your pattern; Think ahead and plan your cuts.
Posture: Sit square in front of the saw making sure you are sitting at an appropriate height, so you can look down at the entire part you are cutting.
If you sit too low and are looking across the part it makes it harder to see what's coming up. 
Sometimes you may find you're turning your body to allow movement of the wood, stop and reposition yourself so you are sitting straight in front of the blade.
Breath:  Remember to keep breathing (I know that sounds silly) sometimes when you cut an intricate part you tense up and hold your breath. This can make it even harder to cut smoothly. Make sure you are comfortable and take breaks as needed.
Speed: The speed (strokes per minute) we use varies from time to time depending on the material that is being cut.  The main thing to remember is “control”.  Intarsia requires accurate cutting, so you might want to experiment with your speed so you can get the best control. We found running the saw about 80% of the speed range on a variable speed saw works great. 
Feed Rate: If you push the wood into the blade you will get a rougher cut than if you slow down and let the blade cut the wood. If you push too hard it can make your cause parts to be "out of square".

Cutting Corners: There are different ways to cut a sharp corner (or point) it will take two cuts. You cannot quickly turn the wood, even with a small blade, to cut a sharp corner. Cut to the corner, then back up the wood, start cutting again leaving a portion of the wood. Once you cut the waste wood away turn the part around and make the second cut to remove the small portions of waste wood.

When you cut curves
, keep your cut or feeding speed constant. If you continually stop and start as you make the turn, the finished edge will be choppy. 

A magnifier really helps to see the lines. A foot switch is a good safety device. If a blade breaks or you need to stop you can easily lift your foot and stop the saw immediately.

Check for Fit: When all the parts have been cut, de-burr the back side of the part and print the number on the bottom (the same number you have on top). 

Do not remove the paper from the top-side at this point. After you have numbered the back side of your project, assemble the parts and check to see how it fits. It’s a good idea to leave the paper on to see if a fitting problem could be from cutting outside of the pattern line.

If you can see the pattern lines then you will need to carefully trim the lines with a new #5 scroll saw blade. This takes some practice. If it is a free-form project practice on some of the outside edges. 

DO NOT SAND TO THE PATTERN LINE it is almost impossible to sand the edge and keep it square.

How to Trim: I like to start by placing the part to the backside of the blade, this way you can get the part right next to the blade without the teeth cutting your it. Then gradually bring the part around to the teeth, you'll start to hear the blade cutting. Practice barely shaving off the line. 

When all the parts fit all right you can remove the paper. 
Remember to CHANGE YOUR BLADES OFTEN! 



Judy Roberts
Judy Roberts

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10 Responses

Judy Roberts
Judy Roberts

January 03, 2017

“I have trouble with reverse tooth blades in that the wood tends to jump up from the “up” stroke. How do remedy this?”
You have to watch how you put the blade in. When you put the blade in, lower the upper arm all the way down, what would be the bottom of the down stroke. You should not see any of the reverse teeth above the table.
You may have the blade up too high in the clamps.

Patty L Hahn
Patty L Hahn

January 02, 2017

I could not get the tension video to produce audio. I would love to see it. Is there somewhere else I can go to view it with sound?

Judy Roberts
Judy Roberts

December 31, 2016

Brenda, When I am sawing I usually have the good part to right of the blade. I think it’s just a matter of what you are used to. All our blades are milled, which produces a seemingly sharper edge on the right side of the blade. The side that is sharper is actually due to a “burr” that is created when they manufacture the blades.

Lloyd Muench
Lloyd Muench

December 31, 2016

I find that I should always cut with the waste side of the line to the right. I, and most people, tend to drift off to one side or the other and by cutting with the waste wood to the right, I drift away into the waste wood.

Meyer Bill
Meyer Bill

December 31, 2016

I have trouble with reverse tooth blades in that the wood tends to jump up from the “up” stroke. How do remedy this?

Diana Copper
Diana Copper

December 30, 2016

This was awesome! Clear and simple. Love the reminders to do it right!

John Cahall
John Cahall

December 30, 2016

Thank you Judy! Very informative. The class I took several years ago with you was very beneficial and a great time.

Brenda Hese
Brenda Hese

December 29, 2016

Thanks for sharing your tips. Not sure why but when I am cutting I prefer to have the piece being cut in the the left of the blade and waste on the right. I find I can get a more accurate cut that way. I assume it is because of the blade (I always use reverse tooth). When cutting a straight line I always have the uncut wood pulled slightly to the left to keep on the line, is this normal?

kurt smith
kurt smith

December 29, 2016

I’m gonna try the highlighter on the outside of lines. I think that will help me. Great tips Judy, thank-you

Don Knox
Don Knox

December 29, 2016

Cutting has been a focus for me over the last two years. For me I need to remind myself, “it is okay if you need to recut a piece”. Getting close to the half line technique. Thanks for sharing this Judy ?

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