Buzzkill

You can shield the motor somewhat, but it's cooled by air moving through the openings, so you probably don't want to eliminate air flow.  Other than trying to make sure you deflect anything coming directly off the belt away from the motor you can use compressed air to keep it clean after every use and probably get by for a while.  I find that over time there tends to be a layer of abrasive dust and such that settles on everything anywhere near the grinder so it's not just the direct debris that will take a toll, but the direct debris will definitely degrade things faster.

If you use the 3/4 hp on a 2x72 grinder it will bog down a lot unless you step the speed down a bit with pulleys.  Since I have not used 1x42 with a .5 hp motor I can't tell you how it will feel in comparison.  Also for any motor you use, if it's not TEFC you will probably have a short lived motor due to abrasive and metal bits getting in the openings of the motor.

We're ok with you posting pictures.  No need to be defiant about it.

I haven't seen anyone mention it and you're probably already aware...... but unless that is high carbon stainless it will not harden and so it's more suitable for a wall hanger or a letter opener than a knife that needs to hold a cutting edge.  A lot of the commonly used stainless is 304 or 316 and neither of those will harden when quenched.  If it does happen to be a hardening alloy then the proper heat treatment is probably pretty difficult to do without a proper heat treating oven.

Either way, welcome to the dark side.  I'm looking forward to seeing what you create next.

I have almost no experience with something like this so I'm just spitballing at this point.  It seems like this may be a good candidate for 3D printing to make the texture in wax, cast in refractory normally used for ribbon burners, then melt the wax.  A close nipple with some pins tack welded on could be set in one end and oriented properly with the wax.  That would let you screw a T on to the end.  Like I said though I have no practical experience here.  I just wish I had the time and money to play around with some of these ideas more.

Well, if you cast the burner tube (or most of it) you should be able to put whatever texture you want in it.  It would also be easy to cast the flare at the right ratio.  Instead of a ribbon burner you could cast a single hole of the right size in a block.  Just a thought.

Thanks!

Yes.  It's hard to see in the pics, but the tanto has a convex grind from the tip down to the main cutting edge which is hollow ground.

A friend of mine who is not a knife enthusiast took the pics, so he focused on some different aspects than I would have if I were taking them.  I still use a "dumb phone" so transferring pics is a PITA for me.

No.  The regulator by itself is sufficient.  You may want to leave the ball valve in place to have a quick shutoff option though.

MbMul175,

No one is going to be able to accurately answer that question.  I can tell you what my T burner uses in my forge at my location at the temperatures at which I forge and with the openings I have in my forge.  The point is there are a lot of variables which will affect how much fuel you use in a given amount of time. 

How well your burner is tuned, your elevation and general weather conditions, the insulation of your forge, the size of the openings, and the temperature you are trying to reach (and a few other factors) will all potentially affect your fuel usage and are not likely to be identical to anyone else's situation.

For rough figuring I get close to 10 hours of time from one 20 pound propane tank when I'm just doing "regular" forging.  If I were trying to forge weld it might be half that.  I don't know because I haven't tried it with my forge yet. My forge is fairly small though - roughly 216 cubic inches of volume.

You may want to stuff some scrap kaowool around the burners in the holding tubes.  That may also affect the tuning of your burners as well.  My forge is smaller than that and the outside shell gets too hot to place a hand on it without injury, but has never gotten hot enough to burn the original paint off the cylinder.

You can turn a big burner down quite a bit, but you can only turn a small burner up so far. You gave 622 cubic inches as your volume I think.  That would put it beyond the capacity of a single 3/4" burner, but still within the range of two 3/4" burners.

Good question, but it may have more than one answer.  The first one is it depends on your tank size.  If you're using grill sized propane tanks that still may not be enough.  When I run a single 3/4 inch T burner on a single BBQ tank for more than a couple hours I can lose pressure.  So, if you don't anticipate forging for too long then you can probably get by with individual tanks of that size.  I just got a Mr. Heater 2 Tank Hook Up Kit for running my single burner to keep the problem to a minimum. That will allow me to still use a single regulator for both tanks. My guess is if you are running two 3/4 or 1 inch (or a combination of both) you'd need 3 or more of those tanks hooked together for long forging sessions.   If you're using 100 lb tanks then 2 of those would probably get you by, but I have no direct experience there and I'm sure someone else out there does.

Another simple solution is to place your tanks in a shallow water bath to keep the tank from getting cold so fast.  You don't want it deep or you risk the tanks tipping over as they empty, but water should contact the entire bottom of the tank to be effective.  A gallon or two of water makes a lot of difference in the tank temperature.  Still, with 2 burners of that size you probably want a separate tank for each or 2 tanks linked together.  Let us know what works or didn't work.  I'm curious in case I decide to build a bigger forge.

With both a 3/4 and 1 inch burner running I would say that yes, that is most likely the culprit.  Mike or Frosty are obviously more well suited to answer the finer points on this, but I believe the 1 inch also needs more space between the end of the burner tube and the first obstruction the flame will hit (opposite wall) in order to function correctly.

I had a dual gauge system on mine for a while, like you would see on an oxy/acetylene system, and there is a significant drop in tank pressure well before it gets frost on the outside or feels particularly cold, especially when it's nearly empty.

It's also possible that you have some debris from the build that collected in your jet, but my money is on trying to pull too much propane from too small a tank too quickly.

I had mentioned that if it were not magnetic it was probably stainless. If magnetic it was probably zinc coated, but could still be stainless.

Sorry.  You are right.  That discussion belongs elsewhere.

Hmmm.  I have no doubt that you can beat modern power tools in some applications, BUT you have some startup time waiting for the forge to get to temp before you can act.  You're also burning fuel during the ramp up and during whatever action you take.  Unless your fuel is free it's probably not cheaper than the electricity the power tool uses for a few minutes. To me all methods have their place and are situation dependent.

If I want to drill a single hole I'm pretty sure I can grab the drill, chuck the bit, and be done before you can light your forge and get it hot enough to punch.  On the other hand if the forge is already hot I'm sure you could punch several holes before I get the first one done with the drill.

“There never was a good knife made of bad steel.”

-Benjamin Franklin

My money is on a Hay Budden that was broken at the waist and a "new" base attached to it.

If the fasteners are your only concern you can chuck them in vinegar for a day or so.  If they are zinc plated it will be gone after that.   If there's no change then they are probably stainless, but either way they are safe to use after that.  Make sure you rinse off the vinegar with a neutralizing solution if possible.

Here's a *possible* test.  Check with a magnet.  If it is not magnetic it is almost certainly stainless.  If it is magnetic it's probably zinc coated steel, but it could still be stainless.  The 300 series of stainless is not magnetic and a lot of stainless pipe is in that series, but it's not a guarantee.

If there's any chance the pipe will get direct flame or significant heat the safe thing to do is not use anything that is galvanized.  If it will be at least several inches away from anything that gets significantly hot you are probably ok, but the risk is on you.

If you look at the user reviews on the Grizzlies you will see that tracking is a common complaint on them. I don't recall anyone ever saying they figured out exactly what the problem is and offering a solution, but maybe read through some and you might get lucky.

That's a little hard to answer without knowing your situation.  If you have to buy everything retail you'd probably have around 3-400 dollars in steel, bolts, nuts, bearings, pulleys, etc.  There are a lot of fairly small pieces, so unless you have a quick and accurate way to make cuts I recommend paying the steel supplier to cut everything to size. It cost me a dollar a cut after 3 I think, but it was worth it since a hacksaw or abrasive cutoff would have taken me hours to do and most of their cuts were square. Mine most likely would not have been. Obviously the more parts you have on hand the less additional cost you will incur with this route.  I didn't (and still don't) have much of a scrap pile with suitable pieces for the build, so I had to buy almost everything.

I still may not have the answer you're looking for, but I can share my experience with you. My main use is also in blade making. I built a 2x72 grinder based on the No Weld Grinder plans.  The first incarnation of my machine used a 1hp motor and two 4 step pulleys for attaining different speeds.  In the fastest pulley arrangement it was fairly easy to bog the grinder down and even stall it at times.  I tripped a breaker with it once and had a few shutdowns on the thermal protection in the motor.  For me having the ability to change speeds is something I would not want to do without.  Final grinds after heat treat are something I like to do barehanded and fairly slowly to avoid overheating blades and to limit the effects of minor mistakes.  A few months ago I got a 2 hp 220v motor and a cheap chinese VFD and switched over to direct drive.  The VFD I got is not rated for dusty environments, so I built an enclosure from an old PC case to protect it.  So far this has worked well and I've had no problems with the power of the machine.  Between the cost of the step pulleys, the pillow block bearings, and the shaft for the previous setup I had almost as much in that as I spent on the VFD.

If you have been working without a belt grinder or a fairly small one with low power just about any 2x72 will seem like a huge improvement.  From my experience I wouldn't recommend anything under 1.5 hp and I also would recommend a way to change grinding speeds.  The 4 step pulley system did give me enough variation in speeds, but the lack of power at the top end was frustrating.

The NWG can be assembled easily in a weekend (maybe in an afternoon) if you have everything you need in front of you.  It does require a drill (drill press is preferred), center punch, measuring devices, a way to cut and square the ends of pieces if you cut them yourself, and a few wrenches, but overall it's pretty simple.

I haven't used any retail 2x72 grinders, so I'm of no help there, but hopefully someone else will have info for you on that front.

I have a couple questions for you before I answer.  What is the main anticipated use for the grinder?  Do you have a 220v circuit to use or do you have to stay on 110v?  Do you have any interest and/or ability to build a grinder yourself?

I welded some square hooks to the sides of my front opening so I can slip a single IFB snugly in and block about half the opening from the top. I have a tendency to "rub" against things when putting steel into or taking it out of the forge, so I prefer not to have things stacked up that I can easily knock over in the process. 

You need to go up in mig tip size.  The diameter of the orifice of the jet should be approximately 0.06 times the diameter of the burner tube.  Keep in mind that mig tips are rated for the diameter of wire that passes through them, not the actual diameter of the orifice.  A mig tip for 0.045 wire will get you pretty close.  You may end up not trimming the tip much or at all to tune it though.

Also your tube length should be 8 to 9 times the diameter, so simply around 8 to 9 inches length for a 1 inch diameter tube.

You may not have seen it yet, but there's a whole thread on coal at Tractor Supply.   In my neck of the woods it's about 6 dollars for a 40 pound bag in either rice or nut size.  It's anthracite, so not ideal for smithing, but easy to get and reasonably priced - assuming you have a TSC nearby.