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Finally learning to braze on new teeth.

Started by maple flats, September 27, 2013, 01:32:27 PM

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maple flats

I've had a Peterson 8" mill since 2005. It came with 2 blades, an 8 tooth for soft wood and a 6 tooth for hard wood. I eventually bought 2 more blades, and had them made by Menominee Saw, sent one to re tooth as a pattern. They did a beautiful job. Then I once took 3 blades to a saw shop and had them re-tensioned and re-toothed. Next I decided to do my own as long as the tension was good. About 4 yrs ago I did 1 blade with OK results, but I used an Mapp/Oxygen torch set. While it did OK the price of the Oxygen made it rather costly to do.
Now I've bought a small Oxy/Acet. torch set and learned how to use it. My first tooth looked quite sloppy, but I kept going. Now, after doing 21 teeth, I really like how they are coming out. I have 7 more teeth to go, and all my blades will be as good as new. I ran the first blade and just made a few cuts to make sure I was getting a good cut and wasn't losing any teeth. It sawed real nice. I can now prep a blade and re tooth it in less than 2 hrs. With a little more practice I'll likely get that down to maybe 75-90 minutes. I guess the best part is that it can be done without shipping the blades and waiting a few weeks to get them back. The second great part is how well they cut. :) :) :)
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

Nomad

     Sounds great!  I haven't had the nerve to take that step yet with my Lucas blades, but your experience may push me a little more in that direction.
Buying a hammer doesn't make you a carpenter
WoodMizer LT50HDD51-WR
Lucas DSM23-19

bandmiller2

Good for you Flats its always nice to service your equipment in house.Did you build a jig [fixture for you politically correct types] to locate the bits.I have watched it done but not done it myself.Does the heat seem to alter the tension in the saw.??I wonder if its easier to properly tension a small saw than say a big millsaw. Frank C.
A man armed with common sense is packing a big piece

tjhammer

frank I built a jig for my blades its simple you don't have to hold anything and all the bits are the same I can take off the old bits clean the saw up and retip in about 20 min if anyone wants I can post afew photos
tj
hammer

sandhills

I'd love to see a few pics of the process if you don't mind, thanks.

tjhammer

I'm having problems for some reason  will try one more time,I drilled and taped an old piece of plate with 5 holes to adjust the saws ht on the plate with this adjustment you can keep the bits in the center of the saw these are in my gallery

  

  

 
hammer

bandmiller2

Thanks TJ,the jig I saw was almost verticle leaning back a little,there was a bolt,adjustable from the rear to center the bits.The solder came in precut "L" shaped pieces. Each bit was touched to the flux and solder then placed on the jig,quickie with a hot fine torch and done.Gravity held the bit down and back. Frank C.
A man armed with common sense is packing a big piece

maple flats

I also built a jig, but I copied the Peterson jig. I just downloaded the manual for the retipping jig, studied the picture and made one. I'll get a picture and post it. I've not noticed any issue with losing temper in the blade. The manual says to use a brazing tip and set the flame so the bright white portion of the flame is 5-10 MM long, surrounded by blue flame. I found that focusing that little white flame at 1/4"-5/16" long works best for me. I first clamp the tooth in place and rotate the blade to meet it (after cleaning any old gook off). Then I very slightly loosen the tip clamp and move the tooth so it centers perfectly in the blade notch when the blade clamp is tight. I then slightly loosen the blade lock bolt and back the blade to give room to flux the tooth and the blade notch. Then I rotate the blade back and tighten the clamp and then just back the clamp bold very slightly to the blade can rotate if pushed hard. I then light the torch (I have the acetylene on 2.5# and Oxygen on 8#) and I adjust the flame as described above. Then I hold the very tip of the white flame on the center of the side of the carbide tooth being brazed. While holding the flame there I hold gentle pressure on the tooth just below the one being heated. When the pre brazing melts the pressure moves the blade very slightly to mate the 2 surfaces tightly. I then keep holding the flame just on the carbide and continue the heat for maybe 15 more seconds. This whole heating time with the flame like I do it takes about maybe 1 minute. Then I remove the flame and look, about 1/2 the time nothing further is needed, the other half I have a gap to fill. For this I hold the flame just above the spot needing to be filled and bring a 3/32 brazing rod to the hot point of the flame, some braze drops to fill the void. Then I repeat holding the flame on just the tooth until it smooths out. If I'm lucky I need nothing else, but on a few teeth I had to file off excess braze so it wasn't wider than the tooth kerf.
I had never brazed before I tried re-tipping about 3-4 yrs ago. As stated above, I originally used a different torch and it was way slow, the current one is much hotter and thus faster. I believe the quicker it is done and the better you get a focusing the little tip of the white flame the better job it does.
The Peterson manual specifies not to hold the flame on the blade. I think this would ruin the temper.
At this time I have done 3 of my 4 blades. I have some other things to get done this week in preparation for a sawing job next Saturday. If I get those done, I'll set back up and do the last blade (an 8 tooth blade) with some pics. I won't however be able to get any action pics while brazing, just some of the steps. After finishing my 3rd blade today (an 8 tooth) I put it on the saw and cut for about 4 hrs. It did well, and best of all, the teeth are still all there. I didn't cut as fast as usual however, because I was training my 18 (almost 19) yr old grandson. I stopped him often to teach the finer points and things to look for. He is a great kid and has been my rt. hand man since he was 7. Even then, he actually worked and did a good days work.
Just a little side story. When he was 8, we were pruning excessive cane growth in the blueberries, (yes, even in season). It was about 85-90 degrees and we were both real hot and sweaty. His mother (my daughter) came with his sister to see if he wanted to go with them to the beach [swimming and a midway (rides)], He said to his mom, "can I stay and work with grandpa?" He has been a great help since and to this very day. He is now in college and this semester is quite demanding (last semester was much easier and he worked an average of 20 hrs every week, and still got all A's and B's). Today is the first time he's been able to break away from his studies, and rather than "hanging out with his buddies" he came to work with grandpa. At the end I started to pay him, which I pay him hourly, he said today was free, for my birthday which comes on 10/1. What a wonderful kid he is. Just thinking about it brings tears to my eyes, how lucky I am!
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

bandmiller2

Flats there was a local company that manufactured high end carbide tipped saws for the cabinet trade. He hired girls that had studied jewelry making in college, their much more dexterous than guys not to mention faster. The little flat "L" shaped pieces of solder were just the right amount, she would put the fine torch on it until it just melted then pull away quick. The way the saw was tilted back and down eliminated any need to clamp the bits, gravity handled it. How do you clean the pockets of broken bits.?? Frank C.
A man armed with common sense is packing a big piece

maple flats

I clean them in 2 ways. As described in the Peterson Re-tipping manual, I apply the tip of the flame I described in the post above on the very edge of the remaining tooth, which is most always slightly proud from at least 1 spot on the blade. I heat it and every couple of seconds I quickly slide a file along that edge of the blade. The piece soon falls off. The rest of the cleaning is done by hand using a good sharp medium bastard file to file away most of the old braze. I then brush it with an SS brush and at that point I am ready to apply the new tooth. If any old braze remains it is just part of the new brazed tooth attachment. I don't dare grind it with a grinder or even a dremel tool because I think it would alter the little cut out pocket on the blade where the tooth goes on. I forgot to mention in my main descriptive post on the steps I take, that I actually rest the edge of the torch tip on the side of the tooth clamp platform to hold the flame exactly where it needs to be, I do not free hand it. I hold the tip so the 1/4" - 5/16" long white flame point just touches the carbide tip being brazed. If I get too close it extinguishes the the flame and I shut off the oxygen only, hold the torch out away from the work and re-light, then I position the flame again. The more practice I got, the less this happened.
When each tooth is brazed, I unscrew the clamp, which is also brazed to the tooth, I use water pump pliers to twist up up. The clamp breaks loose and the tooth remains. I then dip the clamp in a bucket of water and set it aside. Then the tooth holder gets loosened, slid up the jig and off and it gets set in the water to cool while I prep the next tooth pocket on the blade. When that is ready I put the tooth holder back on, it slides down until it rests on the repeater clamp which remains to get each tooth exactly in the same position relative to the center hole of the blade. I then file any braze off the clamp and screw that on, with a new tooth. I carefully position the tooth to be precisely centered on the blade, with the tooth tip positioned in as far as it will go (at a stop) in the tooth holder. Then I flux and braze the next tooth and I keep repeating until all 6 or 8 teeth are on. The original tips on my blades were wider than I now use as I use narrow kerf tips. These tips are barely wider than the blade  where they braze on but are slightly wider at the cutting surface (the teeth are tapered narrower away from the cut surface).
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

bandmiller2

Flats,does Peterson recommend regular brazing rod or something with a little silver content.Some of the silver solders are very strong and flow at a lower temp. I mention it because I retip hammer drills and use silver solder. Frank C.
A man armed with common sense is packing a big piece

maple flats

I'm not sure what they recommend, I just use brazing rod from TSC, (A regional farm supply co.) My teeth are pre brazed which accounts for most of the braze on many of the teeth. I have never had a tooth come off, if I hit something it generally just takes part of a tooth, but sometimes most except right at the braze joint. I don't think what I use has any silver. I'll have to check to be sure.
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

maple flats

I checked the rod I'm using, it is Hobart 3/32 bronze rod. So far, the rod seems to hold the teeth well. I took a few pictures last night, but when I viewed them on the computer they look blurred. Must be that camera either doesn't or I did it wrong but the close ups are bad. If I can't get good with that camera, (I'll check for macro setting) I'll try my phone. It will focus down a lot closer, to show fine detail.
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

tjhammer


   flats the bits are pretined with silversolder and you should not have to use any extra of anything to solder the bit in the pocket I clean the bit pockets with a torch I heat the pocket and brush the solder out of the pocket and the pocket is ready for a new bit,I use black flux wich protects the metal and lets the silversolder flow real easy,I preheat the pocket then push the bit up next to the blade add a little heat to the bit and the solder flows rite in,I have a little roll of silversolder just in case that stuff is like buying gold.the black flux I use comes from enco,if you ever use it you will never use any other on silver solder just my thoughts
tj
hammer

maple flats

I'll look into that, my flux is white. I'm not sure of the name. On the teeth I've done this go around I had 21 teeth I did and about 8 needed nothing extra. The rest did. The teeth are indeed pre tinned but I seem to get a gap in places and when that happens I add the bronze. So far it has had zero failures, but I'll admit, they don't all look real pretty.
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

maple flats

Correction, maybe I have more to learn. I noticed today that I have indeed lost one of the teeth I installed. I guess I need to find some Silver Solder for when I need to fill a void, and I may well need the black flux tjhammer uses. tj, what exactly is the name of it, PM me and let me know where you bought it if you would please. I have some silver solder I use for SS on my maple equipment but I see no % on the mix, I also have 2 other silver solders just a vague. Any help there? I am not experienced enough to get a good braze all the time with no gaps.
As far as clening the pockets with a torch, Peterson strongly suggests you keep the heat on the blade to an absolute minimum so you don't alter the temper of the blade. Please describe better what and how you do it.
Thanks,
Dave
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

bandmiller2

Flats I was always told silver solder is not good for filling gaps and voids, parts must be fit closely.I think with common spelter [brass brazing rod] you would have to use heat to wipe it off. Probibly the original bits were silver soldered on.Have you tried laying the saw on an anvil and shattering the carbide,with safety glasses of course. You will probably end up melting them off as your doing now. Frank C.
A man armed with common sense is packing a big piece

maple flats

I did try a couple, where I laid the blade on a good size anvil and hit it quite hard with a hammer to break the carbide. While it broke the carbide, I still had some attached to the blade. They did not separate. I still had to use a torch, but with no edge sticking out it was harder to clean off without over heating the blade itself. I then went back to heating the carbide only (as much as possible) and just lightly taping the edge every 2-3 seconds until it falls off. Then I clean the pocket with a file. Sometimes I need more heat and a SS brush to get it good.
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

sigidi

Quote from: tjhammer on September 27, 2013, 11:31:29 PM
I'm having problems for some reason  will try one more time,I drilled and taped an old piece of plate with 5 holes to adjust the saws ht on the plate with this adjustment you can keep the bits in the center of the saw these are in my gallery

  

  

 

In the second pic, what are those 'dark spots' on your blade? looks like it is hot spots??

I'm still yet to try doing my own tips, fella who does mine, I courier two blades to him over night for $12 and he brings 'em down when he is finished and going to play golf as he is 160k away from me nowadays - great service  ;)
Always willing to help - Allan

tjhammer

  hot spots they are a big lighting struck red oka caused that it had lots of stress had been standing about 6yrs, wind blew it down it was like sawing stone, I now have 3 saws to be hammered,I sawed a white pine today 3 15ft logs the top of the tree had lots of knots and stress hung me up several times.
tj
hammer

maple flats

I'll get more pics and post them. All of my blades look better than that. I don't think I have any black spots at all.
In the 8 years I've been sawing I only had to get 1 blade re-tensioned, FF member Peachy at Menominee Saw (a FF sponsor) did it, great job. That one had gotten a little hot, but no black spots. Likely letting a blade get so bad it needs to be worked too hard ruins the tension. Keep your teeth sharper and don't force it, you'll need less re-tensioning. Might also be better that my blades have 6 or 8 teeth, rather than just 5. Then each tooth is doing less work. However, I can get a bad chip or even have the end of a tooth break off and I still cut with 5, however I change the blade if I get 2 such chips or tooth tips broken off in a row.
Hammer, I did some more teeth after reading how you do it, and I added no extra braze. They still do look good, however my first sawing with that blade will be tomorrow or Saturday. Going to finish a custom sawing job Saturday. Hit lots of fence staples in the cherry butt log, somehow I set my metal detector to over look iron and steel by mistake, and didn't notice. It usually finds staples before the blade does, but not that time.
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

maple flats

I used the 2- 6 tooth blades last weekend. 1 lost a tooth, the other all teeth held good. I now think that my tooth pocket (mating surface) may be the issue. I'm looking to design a guide to get repeatability in a perfect tooth pocket. I think maybe a roller each side of the blade in the 2 planes needed for a perfect 90 degree pocket for the tooth. This will likely need to be mounted on the hub for precise repeatability. Certainly not my forte` but I have 2 machinist friends who could do it. I think I have buggered up some of the pockets.
My last brazed tooth mentioned in the post directly before this one did not fail. The one that failed appeared to have a larger amount of added brazing rod to fill a void. Likely was a no-no.
Maybe I should have named this thread "trying to learn to braze new teeth"instead of what I named it!
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

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