Machined Brass Back

[lowell holmes]

I'm ready to attach the machined brass back to the saw plate on a saw I am making.

What are the pro's and con's of attaching the back by beating with a hammer, clamping in a vise, or using adhesive like Loctite.

Also, Ron Herman shapes the teeth after floating the teeth on a handsaw and sharpens the teeth in distinctive separate steps. I recently sharpened a 10 point rip saw using his technique and it was very successful.

My saw plate has the teeth (12 tpi) but has to be sharpened. I don't see the need to float the teeth in this case. What do you have to say about this?

OBTW, the saw plate, back, and saw nuts came from Ron Bontz.

[Ryan Baker]

Well, I have no expertise in this at all, but I'm sure some of the experts will come along.

Hammering it on sounds like a way to introduce a variety of distortions and stresses that would not be desirable. Gluing it doesn't seem like what you want to do either. Are you referring to normal Loctite, or something like 680?

If I were making a machined back, I would make it to be a light press fit on the plate, not loose. But if it needs to be crimped down, I would think an even clamping force down the length would work best. Or are you referring to pressing it onto the plate? Even then, I would guess an even squeeze is best.

As far as floating the teeth, the plate you have may well be fine, but it's so easy to check why wouldn't you just check it and see? You have to sharpen it anyway.

[Allen Jordan]

Could you rivet the back onto the plate using brass rod? Probably not a traditional technique, but it would hold nicely.

[lowell holmes]

Since saw plates sometimes slip to be crooked, you can adjust the straightness of the saw plate by clamping it in a vise and tapping on the back to tension the plate into straightness.

If I use adhesive, this would not be possible. So, that leaves clamping the saw plate and closing the slot a bit to provide a friction fit. Matt Cianci hammers on the back and he has a large machinists vise to close the slot a bit. I don't have a large vise, so I'm floundering around a bit trying figure how to approach it.

I've read that some saws are made using adhesive to attach the back. I don't know how those saws could be straightened if they needed adjustment.
I tend to prefer closing the slot to make a friction fit. The back is 16" long, so a huge vise will be required if that is to be done. I probably could achieve the adjustment by clamping it in an 8" vise two or three increments.

I've decided to float the teeth to aid in shaping the teeth when sharpening. I ordered the saw plate to be 12 tpi, that leaves 192 teeth to be shaped.

Thanks for responding.

[Stewie Simpson]

Lowell. I have made a large number of backsaws in the past using machined slotted brass backs. I have experienced only positive results using Loctite to bond the back to the top of the saw plate. Its not overly critical which Loctite you use but I would recommend the metal to metal parts Loctite within the 500 range. Klaus and Pedder use the same process with their backsaws. I have an idea that Isaac Smith crimps his folded backs tight. But I am not up to date with the process Ron Bontz follows. You could pm him to find out.

regards Stewie.

[lowell holmes]

Thanks for responding. I will pm Ron.

[Ron Bontz]

Thanks for responding. I will pm Ron.

Hi. You caught me lurking. I actually use both. I have a press that was made strictly for compressing the slots in slotted spines along the entire spine at once. You do not want to compress the entire depth of the slot as this may cause one side of the spine to give before the other. You will be left with a plate that is skewed in the spine. Place approx. the lower 1/8" of the slot in the press/ vise and compress it but not completely closed. 360 brass will spring back a bit. Check fit. Check plate alignment. Repeat if necessary. A pressure gauge is handy for this. But not perfect. I have a built in limiter as well that helps to keep me from compressing the slot too much. Be forewarned you can introduce some of the same characteristics of a folded back and may need to "tension" the plate a bit. But the slotted spines are milled quite accurately and made to seat all the way down. Once you have it to the point to having to tap the spine off the plate instead of being able to pull it off, you can use the glues if you choose. I sometimes apply a few drops along the spine. Generally at the toe, middle, and heel of the spine. As with any wood working. Glues do not make a joint. They make it better. Lastly, once the spine is on the saw plate, place it on its side on an inspection plate or other nice flat surface. Hold the spine flat on the inspection plate and check the gap along the tooth line, front to back on both sides. They should be equal. I like to do this before I compress the spine as well. It is just a way of making sure the slot was milled accurately to begin with. The spine should be dead flat as well. Nothing worse than a crooked spine. Makes it hard to walk straight. You should be ok on this. I generally check my plates and spines on an inspection plate before shipping them. Best wishes. Ron

[Ryan Baker]

If you are trying to crimp the spine in a normal vice and working your way down the spine, it would be easy to get the clamping pressure different and introduce some distortion. You might be able to extend the jaws using some angle iron (90 deg corner to the spine) or round bar, which would spread out the pressure some and also concentrate it to the lower edge of the spine. You would still have to carefully work your way down the spine. You might be able to do something with seaming pliers (if you could get enough force out of them). A purpose built press would work better.

[lowell holmes]

If you are trying to crimp the spine in a normal vice and working your way down the spine, it would be easy to get the clamping pressure different and introduce some distortion. You might be able to extend the jaws using some angle iron (90 deg corner to the spine) or round bar, which would spread out the pressure some and also concentrate it to the lower edge of the spine. You would still have to carefully work your way down the spine. You might be able to do something with seaming pliers (if you could get enough force out of them). A purpose built press would work better.

Your points are why I didn't entertain doing it. I've decided to use LocTite.

[Stewie Simpson]

Good choice Lowell.

[Tony Zaffuto]

Not pertaining to the spine, but what do you mean by "floating the teeth"?

Thanks,

T.

[lowell holmes]

You take a file and run it over the teeth until you see flat shiny spots on the tip of each tooth. It's like hand planing a board. This insures a straight tooth line.

After the teeth are floated, they are first shaped, then sharpened.

The saw plate probably doesn't need it, but I think it helps to shape the teeth. You can see your progress.

Ron Herman's video on sharpening a handsaw is the best I seen describing the process. Pop Wood sells a download.

[Stewie Simpson]

Hi Lowell. The normal terminology used in saw making for that job task with the flat file is ''jointing the saw teeth''.

http://www.vintagesaws.com/library/primer/sharp.html

Stewie;

[lowell holmes]

Your correct, my bad I guess I was thinking about sheet rock.

[Tony Zaffuto]

That's better! I joint my saw teeth, but have never heard the term float.