back saw sharpening questions

Re: back saw sharpening questions

RJ Whelan

>Kurt �. first, I am not an expert on saw sharpening; I do and have, however, sharpened a lot of saws and this is what works for me:

Disclaimer: I do own a couple of IT saws and when they are ready to be sharpened I will send them to LN for expert attention

1. Lay the saw on something flat (tablesaw, piece of jointed wood, etc) tooth side down and observe if all the teeth come into close contact along the length of the saw. If there are high and low spots you will need to �joint� the saw. Support the length of the saw between a couple of pieces of 4/4 hardwood (I use oak) and file the teeth until they evenly contact your reference flat surface � don�t go overboard with this.

2. Remove most of the set by squeezing the teeth between a couple of pieces of angle iron set in a vise. This is the iffy part � you don�t want to remove all of the set unless you own a saw set to reverse the procedure. I test set by sawing a kerf and then place the end of the saw into the kerf � if it fits pretty tightly the set is probably about right; if it wobbles there is too much set.

3. Draw reference lines across your two pieces of oak � one at +10-15 degrees from perpendicular and one at �10-15 degrees.

4. Sandwich the saw blade between the oak supports with the teeth projecting above the supports and 1/16" and file every other tooth parallel to one of your reference lines � as you file you will be making lines in the oak with the file. When you reach the end of the saw go back and file the skipped teeth parallel to the other reference line. Try to take the same number of strokes on each tooth.

5. Now give each side of the saw a couple of strokes with a fine sharpening stone.

6. Test the saw � if it pull to one side, give that side a couple more licks with the stone. Fuss with the saw until it saws straight.

Good luck ... rj

Re: back saw sharpening questions

Alan Hamilton

>Kurt,

By all means get the Tom Law video. If one picture is worth a thousand words, his video is priceless.

You did very well if after your first attempt at sharpening a saw the saw cut better. More practice will make you better still.

I would not file off all the teeth. I made that mistake more than once. I've had a very hard time trying to get evenly spaced teeth back on those saws. IME if you maintain the original gullets, getting the teeth evenly sized is much easier.

Did I understand you right, that after filing the teeth bent towards you, instead of reversing the saw in the vise, you reversed your file? If that's what you did I think I have an idea about what went wrong.

Alan

Re: back saw sharpening questions

Kurt Loup

>RJ,

I should have started by saying that I jointed the saw first. The last person to sharpen the saw also got every other tooth different sizes, so the teeth were mangled before I started, but I made it worse. Quite a bit of jointing was required to even all the teeth. There was a flat spot made the size of approximately the top quarter of the large teeth before I reached the very tip of the small teeth. The original set was so minimal, if at all, that I had to guess as to which way the teeth were set. I set the teeth with a blue Somax set. I used the number ten setting. I just checked my saw. The teeth per inch are 14. I was surprised that the saw cut straight, but I know it can cut much better with consistent shaped teeth.

I will use your oak support idea. I really think I may have to file off all the teeth and start over. I don't see how I can get them spaced properly without starting over. Thanks for the ideas.

Kurt

Re: back saw sharpening questions

Kurt Loup

>Alan,

You are correct, I didn't reverse the saw. I guess that is where I went wrong. The last guy to sharpen the saw did the same thing, although I made it worse. Due to the gullets being mishapened from the start, I don't think I will be able to salvage the spacing. I'll give it another shot though. Thanks.

Kurt

Re: back saw sharpening questions

John Pappas

>Kurt, I am far from expert in saw sharpening, but I have successfully sharpened both cross cut and rip saws. First thing I will suggest is Leonard Lee's book, "The Complete Guide to Sharpening". It, and another old book, provided all the info I needed to learn what I have learned. It shows a neat jig to use to control the angles necessary to successfully sharpen a saw. The second thing I will stress is this. It is absolutely essential to have good light to sharpen a saw. It is necessary to see the "flats" on the top of the teeth that are produced when you joint the saw. When you shape the teeth you have a point of reference to help you file each tooth to the right height. If you can's see these flats you can't get the teeth even. Even if you feel you have to start over, don't file the teeth off too much. Joint them a little, shape the teeth, joint it again, shape the teeth. Do this several times to get the teeth correctly shaped. Then you can proceed to set and sharpen the newly shaped teeth. Hang in there. If I did it, you can. John

dovetails

Kurt Loup

>By the way, here's a picture of one side of the drawer front. The ends of the tails need trimming, but I'm pleased with the way they came out. I plan to laminate some crotch walnut to the front of the drawer and add a cockbead around the sides.

Kurt

Re: back saw sharpening questions

Kurt Loup

>Pappas,

Thanks. I have Lee's book. I'll check out the saw sharpening section tonight.

Kurt

Re: dovetails

Joe Rogers, Northern Virginia

>This may seem elementary but you are filing the teeth rip correct? This means the file is straight across the saw blade. Dovetailing is a rip function so this is the requisite shape to use. I think RJ's tips should work well for a new filer. His advice has been spot on for years:-) I recently sharpened a backsaw and needed crosscut teeth. I too am not satisfied with the results but like you find the saw cuts much better. I didn't joint the saw to eliminate all of the short teeth. Tom Law said that the short teeth that remain will "come up" with repeated sharpening. I got 85% of the short teeth and stopped jointing to save some metal.

Beware of the optical illusion of the teeth being different sizes caused by the tooth set. Mine were filed to eliminate the flat created by jointing but still look different sizes.JR

Re: dovetails

Kurt Loup, Baton Rouge

>Yep, I filed the teeth rip. I have another saw that I want to file crosscut, but I'll wait until I perfect rip filing.

Kurt