Tips/Techniques Hot saw tip

[CWret]

This is almost too simple to deserve a post - but once you’ve tried it, then it will become standard procedure.


I’ve been doing this since i got my hot saw a few years ago (CanTire with 14” basic abrasive wheel). After a dozen cuts on small angle the saw starts to substantially slow down. This happens much much sooner if cutting thicker stock or heavy tubing.
Use a grinding wheel dresser to give the abrasive wheel new life. (the disc type in the photo)
Cutting speed will double and it’s much less likely to trip the breaker. (It takes 15 to 30 seconds and so far it doesn’t seem to affect the life of the abrasive wheel but the dresser wears pretty quickly)

PS. Not sure - but maybe a more expensive and higher quality abrasive wheel will not benefit as much.

 

[SkookumRob]

The issue with your wheel is the abrasive bond is too "strong" so it is not breaking down and exposing fresh cutting grain (which is the way these wheels stay "sharp") There are wheels on the market that are typically referred to as "Fast-Cut" or "Low-Horsepower" wheels. These have a little softer bond so that the worn grit is released while you are cutting, exposing that sharp fresh grain. Your method is another way to get that fresh grain exposed, by breaking off the worn/glazed grain and binder you expose the fresh grain.

The trade off is always life vs speed of cut. You can have a wheel lasts a really long time but does not cut very fast, or you can have a wheel that cuts fast but wears down quicker.

Here is a link to the wheel we recommend for the low powered chop saws that seems to be a pretty nice balance between the 2 characteristics: https://onlinesupply.ca/Abrasives/Cut-Off-Wheels/Stationary-Cut-Off/KL322628

You will see this wheel is indicated as an "A30N"

The A represents Aluminum Oxide Grain
The 30 represents the grain size (30 Grit)
The N represents the hardness of the binder - this is the important part, the lower the letter grade the softer the bond... so "N" is softer than "R"

This material coding system is not perfectly universal between manufacturers but it should give you a pretty good indication of what you are getting/using!

 

[CWret]

Thanks for that info. I kinda suspected (as I’d indicated) that a different wheel might make a difference. Your suggestion is also at a very competitive price.

 

[Susquatch]

This is almost too simple to deserve a post - but once you’ve tried it, then it will become standard procedure.

I soooooo glad you posted and also that @SkookumRob replied.

I DID NOT KNOW ANY OF THIS!!!

And I use a cutoff saw A LOT!

I have two 14" cutoff saws like that. A cheapo PA and a Ridgid. Both routinely blow the breaker on tough jobs. Sometimes I can actually feel the blade stop cutting. I always thought the work was hardening. If I find the right pressure balance, they usually seem to cut fine. But sometimes it's a fight!

The sides of your blade look sharpened. Do you use that gizmo on the sides or the cutting edge? Basically, please explain how you use it and where you got it.

I'll also look closer at my blades. I inherited a box of a hundred blades. I'm not even sure if they are any good but that's what I use.

Very Cool subject. So glad you posted Craig. So much to learn. Not enough time left to learn everything I want to learn. When my head gets full, it's prolly time to say goodbye.

 

[140mower]

I just keep a knarly chunk of scrap around and when the cutting slows, I dress the wheel with the scrap by lightly rapping the edge of the wheel while under power, and then drag a fresh edge of the scrap back towards me with a bit of a flick. It has served me well in the 15 or so years since learning of it.

 

[TorontoBuilder]

I'll also look closer at my blades. I inherited a box of a hundred blades. I'm not even sure if they are any good but that's what I use.

with a hundred blades you can just toss one when it slows down

 

[CWret]

Below is an Amazon link - but I’m sure there are much cheaper options like PA or CTire. I’m certain mine were not very expensive but I’ve had them for at least a dozen years (or 2 dozen).

https://www.amazon.ca/Grinding-Dressing-Holder-Correction-Device/dp/B07PRFRP3Z/ref=pd_aw_ci_mcx_mh_mcx_views_1?pd_rd_w=ndqXy&content-id=amzn1.sym.96f58934-c509-4a79-ad3d-a3f0b6faede2%3Aamzn1.symc.2b06b7e8-a86c-4e6e-b02c-90d58278f4f1&pf_rd_p=96f58934-c509-4a79-ad3d-a3f0b6faede2&pf_rd_r=YYF57WCQ7YVMJ2GEY35Q&pd_rd_wg=e6fav&pd_rd_r=6d05ef47-5cea-4bba-8f4b-29b54ffde0e0&pd_rd_i=B07PRFRP3Z

This is how I hold it to dress the wheel:

Note that I hold the dresser so that it’s wheels (cutters) are not in the same plane as the abrasive wheel.
In this pic, the one on the left is nearly warn out and the right one is about 1/2 used.



No I do not dress the sides - those marks are from going through 2” sq tube.

 

[Susquatch]

I just keep a knarly chunk of scrap around and when the cutting slows, I dress the wheel with the scrap by lightly rapping the edge of the wheel while under power, and then drag a fresh edge of the scrap back towards me with a bit of a flick. It has served me well in the 15 or so years since learning of it.

I cannot visualize that. Mostly I see shards of the blade going through barn door which I plug with the goop on the floor behind me......

 

[140mower]

I cannot visualize that. Mostly I see shards of the blade going through barn door which I plug with the goop on the floor behind me......

Basically you just tap it enough to crumble the layer that's gone to glass, key word being tap, not "TAP it out of the park!"

 

[Susquatch]

Below is an Amazon link

Thanks Craig, I'll have to give that a try.

When you say different planes, I assume you mean the two axis of rotation are not parallel so the wheel kinda sweeps across the teeth a bit.....?

 

[CWret]

so the wheel kinda sweeps across the teeth a bit

Yes

 

[Susquatch]

Basically you just tap it enough to crumble the layer that's gone to glass, key word being tap, not "TAP it out of the park!"

Reminds me of a joke about a cop and a guy doing rolling stops at a stop sign.

A driver is pulled over after rolling through a stop sign. The police officer asks for their license and registration. The driver complains, "I slowed down didn't I?"

"Well the sign says 'STOP'," said the cop.

"This is absurd, there is no difference" the driver replied.

The officer then opens the door and pulls the driver out. He starts waling on the driver with a baton. He asks the driver, "now, do you want me to slow down or do you want me to stop?"

 

[Aliva]

in a pinch I've used a welding rod. just run the saw and touch the flux of the rod to the blade

 

[MrWhoopee]

I have successfully avoided this problem. Don't own a chop saw, never will.

 

[Susquatch]

in a pinch I've used a welding rod. just run the saw and touch the flux of the rod to the blade

Why does this work?

 

[ChazzC]

I have successfully avoided this problem. Don't own a chop saw, never will.

Every once in awhile I think about getting a cutoff saw (probably cold saw, since I’ve seen hot saws in action); then James (Clough42) will use his in a new video and shows how he places his on the floor in front of the partially open garage door so most of the chips go outside (outside of my garage is the front door to the house).

 

[Tom O]

Turn around? Oooh garage doors?

 

[ChazzC]

Turn around? Oooh garage doors?

James’ shop is in an attached garage; my belt grinders are on a mobile stand in my 2-car attached garage, where I also do wood working and other mess-producing operations.

 

[Tom O]

Ok just wondering I wasn’t thinking of attached garages I’ve only had detached ones …. Except in Victoria where they were built into the basement.

 

[CWret]

Cutting metal:

I have a metal band saw, powered hacksaw, cold cut saw, 45A plasma, many disc grinders, Ox/acc torch, hot saw, parting saw, + the usual files, hacksaws and other hand tools.
There is a place for each and for me they all get regular use.

PS - I’m also experienced with explosives shape charges.