stainless fittings problem

[Mikey D]

i wonder if anyone has any ideas to solve my little problem

ok so i have some dairy fittings to tig weld together , slight problem tho its imperial fitting to metric tube



thats the fitting a 2" to 1 1/2" (16 gauge) reducer which i need to tig to the 40 mm tube (1mm wall)

 

[Mikey D]

oops ok thats the two mated togeter but as you can see the tube is slightly larger o/d than the reduced 1 1/2" end .

i need to find a way to take a bit off the reducer so it too is 40 mm , so roughly 2mm .
theres no way of holding it in a vice as it will become oval

i did try holding it up against my 9" grinder , wearing gloves i might add but there must be a better/ more accurate / safer way ?

any suggestions please

 

[Hitch]

I think removing some of the reducer would be the better option.... Could you not tack it to what its going on, then some carefull work with a flap disc to reduce the height.

 

[Mikey D]

yea thats what i want to do hitch remove some from the reducer ,what did you mean by the better option ?

like i said i did try holding it up against a 9" disc , but i think your idea is good if i mark it with a fine marker pen i would have a line to work too . obviously i dont want any gaps and to keep it square .

the other end welds straight onto a 2" RJT union so i should be able to hold that lightly in a vice (with some soft jaws )

cheers mike

 

[Hitch]

Well, easiest option would be to just weld it up as is... but thats pretty poor.

 

[Mikey D]

yea i dont want to do that it looks crap plus the inside of the tube is on the outside edge of the reducer so hard to hold straight whilst tacking

can you think of any way of machining a bit off , as i have a few to do now and again but the reducers are cheap enough (£2.80)so id buy 10 or so at a time .....

cheers mike

 

[Hitch]

A carefull go with a flap disc would do it, perhaps finish off with a file.

 

[wyn]

You could weld the larger end of the reducer to a lump of something that could be held in the vice.

Then slice off the end to the right diameter with the 9".

 

[Mikey D]

yea i could do that wyn .... a bit more accuracy is required tho

 

[wyn]

If you have access to machine tools is it more of a "work clamping" sort of problem.

If it is then welding it to something as i said would be a bit naff especially if you have to do a few.

 

[Paul.]

Ive got a small jig for doing exactly this, its basically a 6mm plate with a hole in it that the small end protrudes through, then use a flap disc to take the end off the reducer to be level with the plate, the plate has legs welded under to keep it square. useful on site, but in the workshop I tack the reducer to a bar and face off in the lathe.

 

[drivewasher]

Could you not flare the end of the tube to just go over the fitting?
You know like you can gat a tool to make copper tube a bit bigger diameter to fit over the same size tube to avoid having to use fittings

 

[Paul.]

Could you not flare the end of the tube to just go over the fitting?
You know like you can gat a tool to make copper tube a bit bigger diameter to fit over the same size tube to avoid having to use fittings

The idea is to keep the inside smooth, no steps or ridges that can breed bugs thats why we usually purge the tube.

 

[wyn]

Ive got a small jig for doing exactly this, its basically a 6mm plate with a hole in it that the small end protrudes through, then use a flap disc to take the end off the reducer to be level with the plate, the plate has legs welded under to keep it square. useful on site, but in the workshop I tack the reducer to a bar and face off in the lathe.

That sounds good if you are doing a few and have a lathe you could make something along the lines of my pretty poor drawing.

 

[Mikey D]

Exactly right paul , dont want any crevises . dont want a little job facing off a few do you

Your jig idea sounds good although a wee bit of work to make it .

cheers mike

 

[Mikey D]

wyn i like your thinking there ..... could get expensive tho id need to buy a lathe first

 

[wyn]

Ah, right. A lathe would cost a bit.

I can see if you and Tig paul need these reducers cut down there could be a bit of a market for them.

 

[Paul.]

Exactly right paul , dont want any crevises . dont want a little job facing off a few do you

Your jig idea sounds good although a wee bit of work to make it .

cheers mike

Its not that complicated, the only tricky thing is getting the hole the right size,
the bars at the bottom are for clamping down, the plate is about 6" square, I made it when modding a wash down system on a machine made in the USA to interface with an Italian machine, Its a regular problem

 

[duncan_m]

If you have a belt sander you could clamp the sander upside down in a vice and turn it on (might need to cable tie the ON switch).. you could then hold the reducer against the belt and slowly take off the desired amount.. test fitting it as you go.. 60 grit paper perhaps.

Dunc

 

[piman]

Hello Wyn,

I would do a temporary weld on the small end to some inch and a half pipe so that it can be held in a lathe and skim the excess length, then part off at the small end to keep that true. (light cuts only). With the best will in the world it is not easy to grind it off square and level.

Alec