Cleaning metal

[Jimbob17]

Hi I’m making a holder that I’m going to mount on the wall to hold my electrode cases, excuse how bad the circles are this is on the 2nd time I’ve used my plasma cutter. Any tips of getting the circles better next time? Also I’ve cleaned all the rust off and am working on the black stuff (mill scale?) do will leaving that in effect the ability to weld onto it or paint? Thanks

 

[Agroshield]

Any tips of getting the circles better next time?

Cut a circle of plywood using a hole saw and either run the torch around the outside of the circle that falls out or around the inside of the hole in the wood (that way you get two for the price of one).

 

[droopsnoot]

Lidl had circle cutting attachments for their plasma cutter last time I went in. I didn't look in detail as I haven't got a plasma cutter.

 

[Redsailor]

I have soaked black rolled bar and plate in a strong citric acid solution to remove millscale. Leaves a better finish than attacking it with a flap disk.

 

[Agroshield]

I have soaked black rolled bar and plate in a strong citric acid solution to remove millscale.

Vinegar also works. White vinegar is cheap. You can use a piece of butyl pond liner draped over some timbers to make a swimming pool for odd-shapes. For small rod and bar, use a piece of guttering. For larger, use a piece of 6" soil pipe.

 

[prepman]

Hi I’m making a holder that I’m going to mount on the wall to hold my electrode cases, excuse how bad the circles are this is on the 2nd time I’ve used my plasma cutter. Any tips of getting the circles better next time? Also I’ve cleaned all the rust off and am working on the black stuff (mill scale?) do will leaving that in effect the ability to weld onto it or paint? Thanks



View attachment 453798

I made my own...but aliexpress...has loads

 

[Jimbob17]

Thanks for all you reply’s I appreciate it. Prepman do you have any specs or design for the one you made? Could be a fun project once I’ve finished what I’m working on

 

[Morrisman]

For none round or straight cuts I found that spending a little time making a plywood template to follow is a quicker and easier method than cutting freehand then cleaning up with a grinder. Even though my hands don’t really shake freehand cutting always gives a wibbly wobbly edge that needs a good grinding to look decent.

 

[chrismac]

Now you have most of the hole out, I would scribe a circle of the diameter you want and tackle it with a grinding disc edge on feathering out to the line, you will get a near perfect circle in next to no time, better if your grinder has no bottom on the guard like dewalt, some makita have 1/3 rd covered makes it slightly more awkward.

 

[Jimbob17]

Now you have most of the hole out, I would scribe a circle of the diameter you want and tackle it with a grinding disc edge on feathering out to the line, you will get a near perfect circle in next to no time, better if your grinder has no bottom on the guard like dewalt, some makita have 1/3 rd covered makes it slightly more awkward.

I found that the hole is too small to actually fit the grinder to be able to work around it. So I would only be able to fit one side at a time and it probably wouldn’t make a good finish

 

[chrismac]

I found that the hole is too small to actually fit the grinder to be able to work around it.

125mm disc grind it down until it fits in the hole? what size is the hole?

 

[Morrisman]

125mm disc grind it down until it fits in the hole? what size is the hole?

Judging by the Mole grips I’d say 3” diameter, so a die grinder is about all that’s going to open them holes up.

 

[Jimbob17]

That’s a 115mm disc

 

[chrismac]

Judging by the Mole grips I’d say 3” diameter, so a die grinder is about all that’s going to open them holes up.

Maybe my explanation was poor, keeping the grinder horizontal and depending on hole size and disc size which can be reduced, use the edge of the disc to open up the hold back to round.

 

[Jimbob17]

Maybe next time ill make the hole smaller then I can use the grinder afterwards currently if I make them any bigger and I’ll have to weld metal back on because they are currently the right size
Basically it’s someone to out my electrode holder so I plan on mounting it to the wall these are the electrode holders

weldporn® Rod Storage Tube. (Stick Rods)

weldporn® Rod Storage Tube (Stick Rods) weldporn® Rod Storage Tubes to suit stick electrodes. Inventory and organize your filler metals properly 1/8” (3.3mm) nominal wall thickness for superior strength and durability Neoprene seal to keep your rods air and water tight Available in 14”...

ozweldingsupplies.com.au

So I’m going to weld another piece of metal onto so I then bolt it to the wall? Any thoughts on how long I should make the back plate?
Something like this

Google Image Result for https://www.allweldservices.com.au/wp-content/uploads/2022/11/RG301.jpg

 

[prepman]

Thanks for all you reply’s I appreciate it. Prepman do you have any specs or design for the one you made? Could be a fun project once I’ve finished what I’m working on

Not really it's a copy of those in the pic. You have use of a lathe? These pics were early cuts before I burnt the hoses and put up with a leak for years.
Machining something to suit the plasma shield is the tricky bit. I made a swivel...... ramble ramble..sod it!
I'll get it and post the design.


The later ones weren't pretty (pic), loss of air was the cause. Cut the leaky piece out and back to how it used to be. You need a good supply of high pressure > 100psi

 

[prepman]

Thanks for all you reply’s I appreciate it. Prepman do you have any specs or design for the one you made? Could be a fun project once I’ve finished what I’m working on

This an stl file with cutaway, so you can see how it goes together. The cone is to suit the shroud. Mine's a plasma 55 and overall dimensions are ~40mm dia by ~20mm tall. Couple of wheels ~40mm dia for clearance. I used a hex rod to stop twist and another larger brass hex for the pivot point. Not rocket science...just cobbled together to fit.

 

[Jimbob17]

No unfortunately I don’t have a lathe I’m just starting out with metal work and teaching myself to weld. I’m also looking at upgrading the welder as the one I have current is a cheap one

 

[prepman]

No unfortunately I don’t have a lathe I’m just starting out with metal work and teaching myself to weld. I’m also looking at upgrading the welder as the one I have current is a cheap one

In that case £21 ready made is a bargain.

 

[Morrisman]

I constructed a high quality piece of engineering to help cut the fan holes in my trike body. It took a while, but the results were worth it.