Is there such a thing as a water-fed beltgrinder?

A

Alan Molstad

Banned
Joined
Aug 13, 2006
Messages
422
when Im standing at my beltgrinder I have to keep dipping the blade in the water quench tank to keep it cool.

after a while I get to thinking that some guy must have invented a tool where you never need dunk the knife ever....?

You would need some type of belt cover so that you dont spray water all over the shop.
 
I've seen pictures of a spray set up and a wet sponge set. The spray sent a fine mist and the sponge just kind of moistened the belt. I've often thought about setting up a mist of some sort but then I think of the mess. If you get one going, I'd like to see it. It's not that hard with grinding stones but with a belt, you're going to have premature failure if it gets too wet.
 
In the glassblowers shop at work there was a 6 foot tall commercial wet beltgrinder that took 4 or 5" belts that were probably on the order of 132" long or more. It was a beast contraption because of all the cowling to keep the water in. All platen, no contact wheel.

My point is, they're out there....
 
I just been thinking...
I saw a topic here on the forum today about a guy who wants to cool the platten from heating.

Now cooling the platten will not cool the blade at all, so I think that there must be some way to cool the blade so that once you start to grind a blade you dont need to stop and quench....

But yes, it sounds like a big mess to be sure...like mills that use lots of quench are always splashing all over the place,,,,but the idea works for milling tools...
 
There are quite a number of water cooled grinders or sanders made to cut stones.(lapidary) Check the Gem and Mineral catalogs. The problem is most of the belts we use are not waterproof.
I decided that it is a lot simpler to dunk the knife when it gets hot.
My $.02
TJ Smith
 
Yes, Im not ever going to actually build a water grinder,,,I was just thinking about the idea....

One a side note:
I have a Grizzly grinder , and as I grind things I hold a finger or two behind the platten on the platten supports to brase myself.
However as I grind on a blade the platten gets a bit hot after a while.
I started thinking up all sorts of ways to cool the platten down...

Then winter came, my shop in unheated, and right now I have to have a little space heater propped up at the hight of my platten to keep it and my fingers warm....

Over-heated platten is no longer a problem....
 
I bought one from a guy locally.He makes them for grinding stained glass,Its pretty simple and it does make a mess.It's just a little fountain pump in the black sump box wired up to a momentary switch.
I passed up one of those 132" belt grinders from a buddy that does commercial glass work,good advice from the guys on this forum because I ended up getting a kmg:)
attachment.php
 
I'm pretty sure a wet belt isn't going to solve the problem of heating up blades on a belt grinder. Unless you grind under water, there just isn't that much thermal transfer potential in the little bit of water you're getting on a belt that's traveling at high speed.

I use fixtures for some things that don't allow a quick dunk in the water bucket. Here are two thing I've tried that work:

Cold Air Gun: This is a device through which you run compressed air at about 90 psi (high CFM too--gotta have a good, two-stage compressor to feed it). Inside, there are venturi that cause the air to chill as it's pumped through. This creates some very, very cold air that you can position to blast on your part. The problem is that when you're moving that much air, you pick up moisture through the compressor and, unless you have a compressed-air dryer, you get snow coming out of the gun, and then ice, then it freezes up and stops working. (I'm looking for a suitable dryer.)

The other option is the 'mister'. This is the best thing I've used for this problem so far. Again, you use compressed air through a mister head that syphons water and water-soluble oil (so you don't rust your machines so much), and atomizes it into a very fine mist that is sprayed on the part. Steam/Mist is an extremely efficient method of transferring high heat.
There is no splatter because there isn't that much liquid in play. I've found that the mister can keep up with the heat generated by reasonably sharp belts and a little care, which you should be exercising anyway on thin sections.
Use a mister in a well ventilated shop. It's best not to breath the oils in the mist. I use a respirator when grinding anyway and have a huge fan in the wall that blows through louvers right next to the grinder, so I haven't experienced troubles with residue in the shop.
 
I have heard that moisture shortens the life of the belts we use for knife grinding. Just keep dippin and dryin.
 
I think that your best bet is a air quinchure I built glass tempering machine and used air at a low psi to cool and temper the glass. I think that you could use this type of system to cool a knife but I also think that it will send a lot of dust in the air and freeze your fingers at the same time..
 
I had a hand power sander and it used to get what i was sanding hot. I tried alot of things to help cool it down ( even if it only helped alittle ). One trick I learned happened not from choice but because one of my kids was sick. We had a cold humidifier running in the room and I had a piece of wood I was working on . The wood had gotten alittle hot so I put it down for a sec to get something to drink. When I got back the wood was colder then room temp. One of my kids turned the mist where it was hitting the wood. After that I got a cheap humidifier and fixed an end to it that got smaller as it went down. It ended in about the size of an O2 tube used in hospitals ( kind of small ) but the mist was able to be directed to where i wanted it. It did not help me much ( hand sander makes it kind of hard ) but I bet if you had it where it only mists the blade and very little got on the belt you would save your belt and the misted water would cool faster then dunking and save time between dunking even if you still had to have a pan of water around.

I never really thought about making one for my belt grinder ( don't even have the one I had before ) but it would be interesting to see if it still worked. This was one of the older humidifiers that really put out the mist. I am not sure how the newer ones would work. I don't have my belt grinder yet ( waiting for it to come in ) so no way for me to even try it.

Not sure if the mist would be enough but if someone wants to try it they can just put a humidifier next to the belt grinder to see if it does help cool the blade any. The mist would also heat off the belt faster ( I think it should anyway maybe someone can nay our yah my idea ) then water. If someone tries this let us know how well it worked and what you did to make it better ( always a new low tech way to do something from what i see on this forum ). A bunch of bladesmiths should be able to come up with a cheap way of doing this ( from what i see creativity is a key to knife making ).
 
I'm with psycho....while it would be great to just grind away...taking a second to dunk in a bucket gives you a chance to inspect the blade and think a little before moving on.

I would love to stop burning my fingertips...of course...

But sometimes even if I leave a little water on the blade when I put it up to the platen/wheel...it goes around the belt and ends up splattering on me. I imagine you'd have to have an enclosed setup.

Bob Terzoula (amongst others) mentions rough grinding with a wet sponge laid up against the belt. Says it cut down on the static too.

Jury's out for me...would be nice if somebody invented something that worked - without fuss/mess. Would sell great!
 
psycho78 said:
dunking your knife in a bucket takes all of what...2 seconds?
Click to expand...

Good point...

This is a heck of an interesting thread; I keep thinking back to Metals Shop 1, freshman year of high school... first lesson, first day of class, "the bandsaw NEVER runs without the coolant on." More for the health of the tool than the steel, of course. But the same concept of excess friction and heat leading to problems, still applies.

If a guy does choose to just dunk frequently, what's the recommended coolant? Would a few ice cubes in the water, or chilled oil (which I think would stay cool longer than water) be better, or would it even make a difference? I was always taught, if the steel starts to feel hot on your fingers, stop and dunk it. (I never dreamed of wearing gloves while grinding till I read about it here, and I'm 100% against it, as were about 99.9% of the replies when the question was asked, if I recall right.) Also, "blue is bad" when grinding, hehe...

I guess what I'm wondering is, is it all that critical? Assuming a person doesn't totally abuse the steel and/or grinder. I read a series of posts a while ago, by a guy who said he grinds blades as fast and hot as he can stand, then anneals and heat-treats 'em. I would think he burns up belts and maybe motors pretty quick, but if that approach allowed you to grind blades(or finish forged blades) equally good a lot faster, wouldn't it be worth it?
 
Before the HT you sure are not going to harm the steel just by getting it even very hot...
Before the HT I always grind with gloves on...it's so cold in my shop that I have to wear gloves.

After the Heat-treating it is a different matter.
At that point you dont want to get any parts of the blade too hot as that would tend to discolor and perhaps harm the hardness.
 
I run a coolant bandsaw and I run one without( the little ones like pretty much every knifemaker gets eventually. I work in an unheated shop(ok the forge heats it up, but this time of year it takes awhile) and I still grind barehanded. I grind with a bader bm2 with a platen because most of the stuff I do is flat grinding. To keep my qunch bucket clear of ice I add a little antifreze. It can give you stick fingers, but that is better than fried ones. I mostly make my knives out of 1/8 x 1 stock and I grind the bevels all the way to the top. I leave my edges only .020 or half a mm if you like that better. What I've noticed is that if I overheat the blade I wind up with ripples along the edge. So I make sure I don't overheat the blade. I was thinking as I read this post of the actual time it takes to grind in bevels and how many times I dip the blade. For one of my normal knives I think that grinding in the bevels before HT takes 10 min or so and I dip the blade maybe twice that. Ironicly I think it takes more time to clean them up after HT than it does to put them there in the first place. Maybe thats me just being careful. I agree with Dan that it gives you a chance to see your progress. I think that I stop and look at my progress more than I dip the blade. I know not all of you have a grinder this powerful and so the grinding may take more time. But, I think it important to remember that using new belts for ginding in the bevels helps alot too. A sharp tool will cut faster and cooler. On blades of this size( under 10") I put on a new belt for ginding bevels for every other knife. On larger knives its a new belt for every one. A belt done in service for grinding bevels then goes for ginding the outline of the knife. I use about 4 times as many 60 grit belts as I do the finer grit belts. I keep seperate belts for shaping the handle.
As for a water-cooled belt grinder, Yeah it sounds like a good idea at first look, but I think it would interfere with the effiency and versatility of the grinder. I would much rather go with Robs air cushion platen as a way to keep things cooler. My platen get too hot to touch if I'm ginding alot.
Thanks,
Del
 
delbert ealy said:
To keep my qunch bucket clear of ice I add a little antifreze.
Click to expand...

Back when I started making knives I used to just use clean water with just a drop or two of JOY dishsoap in it.

This was fine for the spring/summer/and fall.
But when it became winter I had to come up with a better idea.
I got myself a little "hotplate" and was able to heat a tin bucket of the quench water to melt the ice.

That system worked for the first 2 years...then I switched to useing pure winter car glass clearner. It never forms ice and does not need to be heated to use right away.

Not haveing to warm up my quench has really helped speed things up for me.

Another thing I used to do is use another "hotplate" to heat my texaco type "A" quench oil. I like the quench oil heated to 160 but getting it that hot in the winter was a long, slow job that could take an extra hour sometimes.

Now, I just fire up my forge and heat Rail Road spikes to red hot, then place them in the oil to heat the oil.

There is a bit of flame, but thats fun too....
 
Alan,
Acoulpe of years ago I bought a buch of bottles of the hot melt or wheatever they call it, anyway its similar to the stuff you decribe. Becuse there is so much of it, I have been storing it in my shop. I never thought of using it for a winter quench, but its a good idea. might not be so sticky fingered at the end of a long grinding day.
Thanks
Del
 
You must log in or register to reply here.
Back
Top