using a cutting torch

T

TJ Smith

Joined
Sep 17, 1999
Messages
863
When trying out a #0 tip on my torch the thing kept popping without going out. Once it did go out and one of the tubes going to the tip had a burn going on inside it.The gas one I think.
I'm not to good with a cutting torch.The cut keeps closing up behind the cut. I am cutting 1\8 inch saw blade steel for knife blanks.
Any suggestion for tip size and pressure.How close should the flame be to the steel?
 
I often have to set up a pantograph torch at work. I never have much luck with that size tip either! It seems like not enough O2 blows through to remove the molten metal. At least that's the way I would describe it!!
I would move up to a larger tip and not try to cut as close and burn a wider path. That's the only thing I have found to work!
Neil
 
i know nothing about cutting torches...but you dont want to get your knife steel that hot....i know that for sure....so what are you gaining by using a torch......try friction cutting with a wood bandsaw...works like cutting butter.....my .02

------------------
http://www.mayoknives.com


 
Yeah thanks for the input. I have had better luck with a larger tip and will probably use that.
Far as the bandsaw goes. Whats a friction blade?
This stuff is so tough you can't drill it unless you use carbide blades.
It just strips the teeth off wood blades. Like using one blade to cut another blade???
 
did you lower the pressures on the guages when you went to the smaller tip. 2-3lbs is all the gas pressure you would need with the o tip and I would say no more than 15-20 on the oxy. side. Victor puts out a booklet on tip size and pressuers that can be had at most welding supply stores, hope this helps
 
the reason the tip is popping is because it is dirty or not seated in the head of the torch keep the gas at about 5 to 7 # and the air aroud 35 t0 40 # clean the tip and tighten th e nut a little and this should fix the problem ,now about the cut closing up on you not to much you can do about that your probally running the flame to hot and if you would get a 000 tip it would help but the thickness of the steel and the alloy contents are what is doing it if the cut is welding back shut your are to hot and to slow if you can break it loose after you cut it that is about normal not much more you can do about the slag good luck
 
What DCK8 said is right. Sometimes when the torch pops out it sucks fire inside the torch, the burnt spot you talked about, left unchecked it can burn back up the torch hose to the bottles, not good. If burnback occurs turn gas first leave oxygen on slightly longer to clear fire. If tighting the tip doeesn't stop the problem the torch can be reseated at the weld supplier. The torch should also be equipped with burnback check valves. The carbon content of the saw blade is also partly responsible, hold the tip as far back as possible and still cut the steel cut the pattern oversize and grind back past the blue line and you will have the original temper of the steel. I've done this quite a bit with good results.
 
Okay I have to say that some of the info is incorrect here. In the event of a flashback always turn off the oxygen first! The pressure from of the oxygen in the mixing chamber has caused preignition in the body of the torch O-Rings should be checked prior to relighting. The popping is generally caused from leaks tip may not be seated properly, or orings may need replacing. Gauges and hoses can be checked for leaks by performing a pressure drop test. The kerf can be minimized by pointing the torch in the direction of travel with the preheat cones about 3/16" above the plate being cut. For 1/8" material use 000 tip cleaned, with acet. about 3lbs. oxygen about 20lbs. travel speed needs to be pretty fast the combination will eliminate much of the slag that your experiencing. Need more info email me I will help if I can.

BTW Although I havent tried it I dont believe you would have very good results with the damascus the layers deposited with flame spray would be to thin. There is a large amount of powdered metal alloys and ceramic materials for the process. The newer process for appling is a Plasma Spray Process
less heat affected zone which minimizes distortion. They may be doing the process with a laser now!
 
You must log in or register to reply here.
Back
Top