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So what options do I have??? Dross removal & clean up.....

Posted: Wed Jun 07, 2017 6:47 pm
by Steambike
I am wondering how you guys clean & prep your pieces for paint / powder / whatever you finish with.......
So far I have been using a "flap" disc on my grinder which works ok but doesn't leave a nice finish, i tried wire wheels and the finish is better and it's quicker but the resultant "porcupine" look doesn't suit me :)
I have a ton of reasons for avoiding the Muriatic acid, kids pets -30c winters to name a few......
I figured a drum sander would be the way to go, but that seems like it may not work as well as I had hoped for..based on other posts... sand blasting is I guess a possibility, i have a small cabinet, but not big enough or powerful enough (compressor wise) so I am considering flap disc followed by drum sander.......or possibly building a "wire wheel machine"
So please, aside from the acid, what do you guys do???
I also have to get my cuts better so there is less dross!

Re: So what options do I have??? Dross removal & clean up.....

Posted: Mon Jun 12, 2017 3:33 pm
by larrycameron44
Hi, I don't use muriatic acid but do use a 150 litre container of water mixed with some sodium bilsulphate. It use probably 4 cups in that and add another 2 cups maybe once a month. Soak 24 hours and the dross just wipes off. How safe is it? It's a granular white powder that swimming pool companies use to adjust water acidity.
You can dip your hand in it, if you have a cut, it will slightly sting so it is very diluted.
I know you said an alternative to acid but just another thought.
You mention that you have a lot of dross. Let us know what thickness you are cutting and what plasma source, amps, ipm, volts etc and we can help more. But generally speaking dross is caused by to much height and too slow.

Another method I saw recently to remove dross was a needle scaler pneumatic. A video was posted showing use. It worked well.

Larry

Re: So what options do I have??? Dross removal & clean up.....

Posted: Tue Jun 13, 2017 12:18 am
by Gamelord
MSDS info:

Sodium bisulfate is a diluted crystalized version of Sulfuric Acid which is very irritating to the skin and can cause severe eye damage if contact occurs. Also, swallowing the chemical can cause symptoms, such as diarrhea, vomiting, and low blood pressure. In addition, it is considered acutely toxic according to the U.S. Environmental Protection Agency as noted in the Pesticide Action Network of North America database.

First-aid measures include seeking immediate medical attention and not inducing vomiting if the chemical is swallowed. Also, MedLine Plus notes to immediately drink water or milk unless otherwise instructed by medical personnel or if the person is unable to swallow due to convulsions or vomiting, for example. If the chemical gets on the skin, wash with water for at least 15 minutes. If the chemical is inhaled, move to an area with fresh air.

Re: So what options do I have??? Dross removal & clean up.....

Posted: Wed Jun 14, 2017 4:51 am
by larrycameron44
Interesting as it is for sale at all our swimming pool supplies shops and hardware stores. It is also commonly called "ph Decrease" as it is used for lowering the ph if your swimming pool :)

I guess if you put the crystals on your skin or in your eyes, these things as Gamelord points out would happen. But 2-4 cups in 150 litres of water, it is very diluted.

Cheers
Larry Cameron
RusticMetalArt

Re: So what options do I have??? Dross removal & clean up.....

Posted: Wed Jun 14, 2017 1:35 pm
by Steambike
That would be an interesting alternate to muriatic, so thanks for that, but I think i'll stick with mechanical methods for now......i'm going to try the needle scaler for some bits too!
I will post some pics of my cuts, it dawns on me that I don't know how much dross is too much....maybe it's acceptable????
I will also post up my settings and see what you guys think.....here are the settings I can remember off hand (basically book settings)
I'm running a Hypertherm powermax 45xp on 45A at 250ipm with finecut consumables and currently cutting some 16 gauge cold rolled sheet......