removing dross on fairly delicate work

[Jelly_Sheffield]

If you're doing these on an ongoing basis I would be tempted to build a "Blanchard grinder-ish thing" using a mag chuck, weld positioner, belt sander and some chicken wire... Struggling to describe the idea concisely in words, I will go find a bit of paper.

This sort of articulates my hare-brained contraption:

The idea being that as the weld positioner slowly rotates the workpiece under the belt-sander, it's also winding a wire rope that pulls the arm across the workpiece.

Wire the sander and positioner cables into to a contactor that's turned off by a limit switch once the arm reaches the center (plus obligatory momentary on and E-stop buttons), surround with a frame and some chicken wire/mesh as a guard to stop you accidentally wandering into the knee removing zone...

and Et Voilà! You have a janky, "Blanchard Grinder-ish Thing" that might just do the job.

It was a bit big to draw on the back of a fag packet, so I made do with a sausage roll bag from the bakers... But I think the presentation may be entirely commensurate with the quality of the idea.

Edit:
Spot the deliberate mistake with how I drew it from the top...

Here's a corrected view of how the wire rope would need to run.

 

[Gareth J]

Has me wondering if there is a tool to fit a grinder that will fit blunt lumps in a disc. Like a hoof trimming disc but fitted with inserts wint no angle;

Demotec DL Disc – Hoof Shop

hoofshop.co.uk

Should provide the necessary repeated clonks with a bit of inertia behind them without swinging the arm about.

I suspect an air chisel may be a bit hard to control and fiddly to use but if you weld a slightly wider (~2"..?) flat edge onto a bit might both speed up work and make it easier to handle.

 

[awemawson]

There are those on PlasmaSpider that swear by a soak in vinegar for 24 hours to remove light dross, and if the plasma cutter is set correctly the dross should only be light.

This is why a few posts up thread I suggested a soak in an acid, as vinegar is after all acetic acid.

 

[chunkolini]

Dross is fairly light.
I'll post pics when I get into work.
But these things are pretty big and there are 50+ of them to deal with.
New compressor and air chisel today.
I'll see how that goes.
Big thanks for creative suggestions

 

[DAPPH]

Dross is fairly light.
I'll post pics when I get into work.
But these things are pretty big and there are 50+ of them to deal with.
New compressor and air chisel today.
I'll see how that goes.
Big thanks for creative suggestions

Everybody wants or needs a compressor Chunkolini , now you can make an air tool locker with two 6x4 steel doors for all those must have air tools.

 

[DAPPH]

Due to me being crippled in my back and shoulders I pondered on you cutting position .

I had a thought about a table for hand plasma cutting , make it big enough to take an 8x4 sheet with an inch extra all round to get an 8x4 sheet in or out of a clamping frame . .
Pivot the frame centrally like the old tip to store tables and use a chain hoist to lift the plate /sheet into the frame vertically . Have the tip & tilt mechanism in a vertical slide so you can also use the hoist to adjust the height as well , that way you can plasma cut at a slight angle in the vertical and always cut without much bending or reaching over .ur up . T'would be like standing in front of a big black board and using a plasma cutting torch instead of chalk with no need for support bars in the frame

 

[julianthegypsy]

Due to me being crippled in my back and shoulders I pondered on you cutting position .

I had a thought about a table for hand plasma cutting , make it big enough to take an 8x4 sheet with an inch extra all round to get an 8x4 sheet in or out of a clamping frame . .
Pivot the frame centrally like the old tip to store tables and use a chain hoist to lift the plate /sheet into the frame vertically . Have the tip & tilt mechanism in a vertical slide so you can also use the hoist to adjust the height as well , that way you can plasma cut at a slight angle in the vertical and always cut without much bending or reaching over .ur up . T'would be like standing in front of a big black board and using a plasma cutting torch instead of chalk with no need for support bars in the frame

I like that idea!

 

[chunkolini]

I will play about with angling my plasma table. Probably the slobbish way ans just tack extensions on two of the legs. I dimly remember a student suggesting that to me a while back.
it would possibly help my knackered back. Crushed T11 vertebra in 2014. Air ambulance job.
Dross removal? heres a typical photo.Not a huge amount but it has to go. About 20 minutes per leaf with a cold chisel but deadly boring

Air chisel is way faster but Oh!! the noise!! most of it just falls off due to the impacts. Ear defenders a must.
Decisions time. Not sure which way to go

 

[chunkolini]

Interesting idea from Jelly

It was a bit big to draw on the back of a fag packet, so I made do with a sausage roll bag from the bakers

also smoking is bad for your health
I do this all the time design machines and contraptions.
it has made me wonder about trying my big belt sander.
but really it needs knocking off not grinding off./ I tried a lumpy disc on a an angle grinder but it spins too fast.
A [ushbike sprocket on a cordless drill was not too bad. idea! a motorbike sprocket if I can find one

 

[chunkolini]

A solution sprung to mind at about 3.00am this morning. I dismissed it at first but figured give it s go.
My reciprocating saw and damaged blade.
Not bad, fast and gers almost all of it off. Go in very flat and skim the surface. Noisy but nowhere near as bad as the air chisel.

 

[Erie Fred]

That slag has a certain look to it.
I'll ask again, what is the table your cutting on ?

 

[chunkolini]

That's sat on my welding bench
I'm cutting them on the slatted bench in the earlier pic
I must have a go at scrubbing it off with a hard brick as suggested earlier

 

[Erie Fred]

That's sat on my welding bench
I'm cutting them on the slatted bench in the earlier pic
I must have a go at scrubbing it off with a hard brick as suggested earlier

Can you rig up a water tray ?

 

[chunkolini]

I'd thought of it; but 8x4ft too big.
I played about with a small one years ago. In idea I should return to for teaching and small jobs.

 

[Erie Fred]

I'd thought of it; but 8x4ft too big.
I played about with a small one years ago. In idea I should return to for teaching and small jobs.

try a little cake pan for an experiment.
keep the water within 1/2" of the bottom of the metal.
The steam is minimal, and the part stays cooler, your slag looks like some welding/melting is going on.

4 x 8 table, I made my water tank 1" bigger all around than the plate size.

 

[dave h 2]

If I have water that close it splashes everywhere

 

[Erie Fred]

If I have water that close it splashes everywhere

Oh yeah.


E-V-E-R-W-H-E-R-E.......

Yet, for some reason, it doesn't for ME.

Must be something in the water in your area eh ?

 

[dave h 2]

It's all about ME
US water is thicker or the cheap and cheerful supermarket 30A plasma doesn't need the 4.5 Bar they set it for all I know is that with 1/2" of water in a 3" deep A3 size tank things get a bit wet.
I should add it's a non pilot Torch so no sparks on top

 

[Erie Fred]

It's all about ME
US water is thicker or the cheap and cheerful supermarket 30A plasma doesn't need the 4.5 Bar they set it for all I know is that with 1/2" of water in a 3" deep A3 size tank things get a bit wet.
I should add it's a non pilot Torch so no sparks on top

1/2" deep in a 3" tank ?
and your 4.5 bar is around 65 psi, why go lower ?