Thread: First saw build

I had a bit of time on the weekend to put into making some saw bolts. Yes, I know you can buy them, but I wanted to make my own. Overall, I've spent more than it would have cost to just buy the saw bolts, but that includes heaps of brass stock which I can use on other projects, as well as brazing rods, etc.

I did consider buying some great big brass rod, and just turning it down on the lathe, but that would take a long time, and seemed a waste of good expensive brass, so I bought some flat bar, and some 4mm rod for the shafts. I cut short lengths of both and brazed the rod onto the flat bar, and then turned the head round from there, and tapped the end of the rod. I have never done brazing before, and had a couple of false starts, but once I got it sorted, it worked really well, and adds another skill to my arsenal. I hope to find lots of brazing projects in the near future. (Just for the record, I used 15% silver brazing rod, and Cigweld Nr. 2 GP brazing flux, both from Bunnings)

The nuts were also made from flat bar, cut into squares, drilled and threaded, and then turned down to the right diameter and thickness.

I left them with the 400grit sanding marks off the lathe, rather than polish them to mirror finish, and hit them with a quick airbrush of nitro-lacquer.

In the end, it took most of the weekend to make the bolts, but I'm very happy with the result. I probably spent around $100 on brass, brazing rods and flux, but then only used a very small portion (maybe 5%) of the materials that I bought, so it doesn't really count, right?

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Hey, I'm not sure what happened. I came back to add a little more to this thread, and the photos of the completed saws are missing! I was sure I posted them a few weeks back. Oh well, I'd better finish the story...

Once the bolts were made, it was a matter of putting it all together. I superglued the blades into the backs, slipped the handles on the end, drilled a few holes in the blades, and put it all together. Drilling the holes was a bit of work. I very quickly discovered that saw still will blunt a normal drill bit completely beyond usefulness before it gets through the saw blade. However, with a grinder on hand and no other options, I just alternated the drill bits between the drill press and the grinder, blunt-sharp-blunt-sharp-blunt-sharp. With a few different bits on the go, I managed to get all the holes drilled. Luckily I'm pretty confident freehand sharpening drill bits on the grinder. I used a bit of cutting oil, but even still, I may have destroyed the temper on some of my drill bits.

Another evening was spent filing and setting the teeth. I filed the dovetail as a rip saw, and filed the tenon as a fairly aggressive cross-cut saw. I think the teeth on both might need a little more set, as it's still pretty tight in the cuts. My tooth setter is a bit dodgy, and after lots of fiddling, I've called it good enough. I'm sure I'll work on it again next time I actually have a project to use it for.

Anyway, the end result is a pair of fully working saws...

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OK, back to where we left off...

The final detail I had planned was to add a saw stamp onto the blade. After drawing up a few ideas on paper, I came up with one I liked, and designed it properly in CorelDraw. I ordered a dry photo etch kit on ebay, used for etching circuit boards. There's plenty of instructions on the web of how to use these kits, so you can read about it there, which I did, then promptly forgot the instructions, mucked it up royally, and started over, and kind of made it up as I went along. For anyone who hasn't seen photo etching before, the idea is to print the design onto transparency, then put the photo etch sheet onto the saw, covered by the design, expose it under UV (I used a large UV-emitting flaming ball of hydrogen that I had lying around 93 million miles away), and then develop that to leave an acid resistant etching mask on the saw blade. Here's a photo of the developed etch-resist, with the design folded over to the left...

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Not perfect, but I was pretty happy with that as a first try (well, OK, third try, but who's counting). I wasn't keen on the idea of putting my whole saw into a hot acid bath, but I read about selective electro-etching using a Q-tip, and discovered on a few test pieces that it actually works really well. Using a beefy 12V power source and a dipping solution of vinegar and salt, I spent about 10 minutes electro-etching over my etch mask. Here's a photo of before and after, and the 3rd photo is after the etch resist was removed. You are supposed to use a chemical bath to dissolve off the etch resist, but I found a stanley-blade paint scraper worked really well.

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Overall not a bad result. Obviously some solution has leeched under the resist. The resist is supposed to be ironed onto the surface, but after an early failure where I melted the resist into a gooey mess, I didn't heat it on, but just stuck it down. It was just sticky enough to stick in place, but I think it probably needed a little bit of heating to stick properly. Next time I will iron it on very gently. Fortunately, the resist was still intact, and the actual etching only happened in the right places, so a quick brush up with WD-40 and 180grit paper brought it back, and the letters came out quite clean.

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Not perfect, but overall, I'm very happy with the result, and have learned several new skills along the way. Hopefully these saws have plenty of projects to look forward to, and who knows, they might even survive to pass down to future generations of woodworkers.

For a first effort there fantastic if they were your tenth attempt they would be fantastic.

I like your approach to the saw bolts too.excellent problem solving there.
Blackburn tools on the net sell a drill bit for going through saw plate.
Get one if you can you will love them.
They cut it almost like butter well nearly.
Ian W i think has used tile cutting bits from Bunnings too cut his saw holes.
I haven't tried them yet tho
Some more pics would be great if you can

Cheers Matt

Great results.

rather than ironing on the resist, maybe you could use a hairdryer or the reverse side of the saw plate?

Wow. I am incredibly impressed. Not even in a "good for your first try" kind of way. Those are really, really great.

Very nicely done

David,

Great job! I never got the resist with chemical etching (FeCl₃) to work well so I'm staying with laser. For me it's easier and cheaper.

Cheers,
Rob

I considered lasering it, but the photo etch will give finer detail. It's also a bit more organisation for me to go visit a laser, as I don't have one myself. Do you use the spray on lasering stuff, or do you have access to a big enough laser to etch the metal?

very nice saws - really should finish mine (or at least start them)

really like the etch

The guy I have do it doesn't use Thermark, he says it gives poorer results and is considerably more expensive. He has a LaserStar fiber laser marker that has 40W output. Very fine detail and deep etches are easy.

@rob_streeper - Yes, my son used something like thermark on a school project, and 6 months later, the black has faded a lot, and with a little use of the saw, I think it would rub off. The LaserStar equipment looks pretty serious, so it should do a pretty nice job!

Originally Posted by DSEL74

rather than ironing on the resist, maybe you could use a hairdryer or the reverse side of the saw plate?

I might try this next time. A hair dryer would give a lot more dynamic control over the heat, allowing me to go until it looked right.