I've got an old Gold Dollar straight razor that I started straight shaving with. I dropped it an chipped about a 1/4 of an inch diagonally off the blade. I set it aside and forgot about it until now and told my uncle I was gonna get a bench grinder and even up the broken end of it. He bought me one but before using it, I've got a question. The bench grinder is 2.1 amps, has 6 inch wheels and the box says it's 3465 rpm. Is that ok to use or not?
Break temper?
- Thread starter ZeroMinusOne
- Start date
It's usable, but it will be very easy to over heat the thin sections of the razor. Grind some similar thicknesses of scrap steel to get a feel for how fast the steel heats up. If you see any color(bronze or blue) that's too much heat. The heat build up is a time, speed, pressure thing. Your speed is fixed, so just rely on light pressure for short durations between cooling the blade in water. You need to stay below 400º F which sounds like a lot, but it can be exceeded in an instant on the thinner sections. You can grind pretty heavy near the spine and kind of sneak up on the thinner sections. Drawing some color away from the working edge will not really hurt anything should it happen.
rbscebu
Girls call me Makaluod
I would say no, it is not ok unless you can keep the water flowing over the steel that you are grinding. This also goes for grinding a blade with even a Dremel at very low speed. The temper of steel can be altered with a temperature of just a little over 200°C. You will not see any colour change until the steel gets well above 200°C. By then it is far to late.
I use an old Craftsman 6" grinder with similar specs to do just that. Works fine for me but I'd suppose that it would not be a 'suggested' practice by some. I can't afford more than that so that's what I use.
Yes, being mindless with that grinder can lead to catastrophic failure, injury, etc.
I keep a glass of ice water on the bench next to me, and dunk the blade religiously. Keeping the thick parts of the blade well chilled will help you not blow temper at the edge.
The trick is to go very slow, and take off tiny amounts of material incrementally.
Make sure the wheel's rotation is such that it goes 'with the grind' and not 'against the grind' so you don't grab the razor's edge make things worse. In other words, if the wheel is spinning toward your feel, then the spine is 'up'. Goof on this 1x and chances are that you'll shatter the blade and shrapnel will fly. Not fun.
Wear gloves, eye protection, face protection isn't a bad idea either.
if you want to drop the RPMs, get a 4" wheel.
Yes, being mindless with that grinder can lead to catastrophic failure, injury, etc.
I keep a glass of ice water on the bench next to me, and dunk the blade religiously. Keeping the thick parts of the blade well chilled will help you not blow temper at the edge.
The trick is to go very slow, and take off tiny amounts of material incrementally.
Make sure the wheel's rotation is such that it goes 'with the grind' and not 'against the grind' so you don't grab the razor's edge make things worse. In other words, if the wheel is spinning toward your feel, then the spine is 'up'. Goof on this 1x and chances are that you'll shatter the blade and shrapnel will fly. Not fun.
Wear gloves, eye protection, face protection isn't a bad idea either.
if you want to drop the RPMs, get a 4" wheel.
I would definitly advise againts it. The thin section of a razors blade heats up very easily and it happens in a second. Unless it is a grinder that allows the blade to be kept wet it is very hard to prevent overheating.
The best was I have found is to use a Dremel on the slowest speed. Rest the cutting edge on a large ice cube as you grind the tip. As the heat moves closer to the cutting edge it will melt its way deeper into the cube and cool itself down. Even still, keep dipping the blade in water often to keep the rest of the blade cool. It will take a while, but slowly is the only way to grind a straight razor.
The best was I have found is to use a Dremel on the slowest speed. Rest the cutting edge on a large ice cube as you grind the tip. As the heat moves closer to the cutting edge it will melt its way deeper into the cube and cool itself down. Even still, keep dipping the blade in water often to keep the rest of the blade cool. It will take a while, but slowly is the only way to grind a straight razor.
I use dremel tools for this stuff also. Thing is - I've seen more blades cracked and 'burnt' up by dremels than anything else.
Dremel's RPM range is like 3-35000 k, so even at 'slow' the heat-creation potential is still there. A belt grinder is optimal, I suppose, but still not without liability and, unfortunately, unaffordable.
I prefer the dremel for taking down a heel/stabilizer because the maneuverability of the sanding drum is better. For reshaping the toe I prefer the grinder. I have taken the toe off several GDs with a dremel though. Six of one, 1/2 dozen of another. Both methods require being extremely safe and going very slow.
FWIW - I use a 180x wheel on the grinder for this. With a quick light touch things go well. The lack of pressure is key.
The conditions needed to create a heat issue are a possibility but they do not have to occur. Just because something 'can' happen or someone 'imagines' it will happen - doesn't mean it is going to happen.
I've reshaped maybe 20-30 blades, no issues with any of them. If I am working outside during the winter I don't even need to chill the blade.
Most (maybe all) of the time, when I see a blade that has temper issues from 'restoration' malpractice, it's from someone misusing a buffer - or trying to polish the blade with a dremel.
To avoid all possible issues, in theory, one might use a diamond plate and work it manually. That would probably be the 'safest' method.
In general, I don't recommend any way, I just do it how I do it because it's what I have on hand and I am comfortable doing it that way. Mostly, I think it really depends on the person, their skill set and ability to absorb a total loss in case of failure. Even with a 'perfect' tool set, there are still risks involved.
No matter what though, take precautions, and wear protective gear.
Dremel's RPM range is like 3-35000 k, so even at 'slow' the heat-creation potential is still there. A belt grinder is optimal, I suppose, but still not without liability and, unfortunately, unaffordable.
I prefer the dremel for taking down a heel/stabilizer because the maneuverability of the sanding drum is better. For reshaping the toe I prefer the grinder. I have taken the toe off several GDs with a dremel though. Six of one, 1/2 dozen of another. Both methods require being extremely safe and going very slow.
FWIW - I use a 180x wheel on the grinder for this. With a quick light touch things go well. The lack of pressure is key.
The conditions needed to create a heat issue are a possibility but they do not have to occur. Just because something 'can' happen or someone 'imagines' it will happen - doesn't mean it is going to happen.
I've reshaped maybe 20-30 blades, no issues with any of them. If I am working outside during the winter I don't even need to chill the blade.
Most (maybe all) of the time, when I see a blade that has temper issues from 'restoration' malpractice, it's from someone misusing a buffer - or trying to polish the blade with a dremel.
To avoid all possible issues, in theory, one might use a diamond plate and work it manually. That would probably be the 'safest' method.
In general, I don't recommend any way, I just do it how I do it because it's what I have on hand and I am comfortable doing it that way. Mostly, I think it really depends on the person, their skill set and ability to absorb a total loss in case of failure. Even with a 'perfect' tool set, there are still risks involved.
No matter what though, take precautions, and wear protective gear.
Assuming that PPE and safety is understood and practiced, there is very low risk involved here.
It's a Gold Dollar!!!!! And a damaged one at that!
If it's over heated it will likely be only at the very toe. And if it's totally ruined it's only an already damaged Gold Dollar. The experience will be well worth the cost of the razor.
This is the kind of thing where a Gold Dollar is the most suitable razor to be learning with.
If I were doing this in my shop on my belt grinder I would be using a SFM (surface feet per minute) of around 900 as I neared completion. A six inch wheel will put the SFM in the range of roughly six times that. A smaller wheel will reduce the SFM proportionately. All of that said, I have no doubt that I would be able to accomplish the task with the grinder described without over heating the razor.
It's a Gold Dollar!!!!! And a damaged one at that!
If it's over heated it will likely be only at the very toe. And if it's totally ruined it's only an already damaged Gold Dollar. The experience will be well worth the cost of the razor.
This is the kind of thing where a Gold Dollar is the most suitable razor to be learning with.
If I were doing this in my shop on my belt grinder I would be using a SFM (surface feet per minute) of around 900 as I neared completion. A six inch wheel will put the SFM in the range of roughly six times that. A smaller wheel will reduce the SFM proportionately. All of that said, I have no doubt that I would be able to accomplish the task with the grinder described without over heating the razor.
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I used a bench grinder to fix the toe of a chipped vintage razor. No issues. As mentioned, you must pay attention to temp and obviously safety..... but it is definitely doable.
That being said, so is walking while chewing gum and I have met men that would struggle to accomplish that task LOL
That being said, so is walking while chewing gum and I have met men that would struggle to accomplish that task LOL
I use a water cooled belt grinder for knife and razor work. Unfortunately yes, they are expensive. I got mine for $100 by watching eBay like a hawk.
Vic is spot-on though, as usual. If you are careful and go slow, keeping the blade cool by dipping it in water every few seconds you should be just fine. DON'T press hard, use gentle (flyweight - little if any more than the famous "weight of the blade") pressure and take it slow. If you press down with any pressure on the blade when the thin section is being ground you can absolutely lose temper in an instant.
Vic is spot-on though, as usual. If you are careful and go slow, keeping the blade cool by dipping it in water every few seconds you should be just fine. DON'T press hard, use gentle (flyweight - little if any more than the famous "weight of the blade") pressure and take it slow. If you press down with any pressure on the blade when the thin section is being ground you can absolutely lose temper in an instant.
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