Locking nut to stud - superglue or studlock?

[gidon]

Thanks very much Chas - that article on silver soldering was great!
And appreciate the clarification jason - does seem to be a fair bit of confusion but think I get it now.
Anyway have ordered some gear so will let you know how I get on - really appreciate everyone's help - it's a minefield!
For everyone's information I looked into getting a propane cylinder and the kit jason recommended from machine mart but the smallest tank (3.9kg) still worked out at £45. Plus £25 for the torch + consumables - was getting a little pricey.
Have gone for this torch from Screwfix: Benzomatic JT539T which will attach to a MAPP cartridge that I'll pick up from B&Q. This torch seems to give about the highest quoted output I can find for a bargain price of £16.99. (Not sure how this compares to a hose torch + propane cylinder - can't find any quoted figures). (Toolstation also do the MAPP cartridge (£10.76) as do others).
And have ordered the 1.5mm easyflo stuff and a 50g tub of flux recommended by jason from here(made up a £10 order for free delivery).
Weird how nowhere seemed to do everything I needed (actually Tilgear came close but their blow torch is £60 odd) - but thought I'd include all the links since this seems like the cheapest way of having a go at this if anyone else is interested.
Cheers
Gidon

 

[jasonB]

Depending on burner diameter a torch will put out around 8000w, but the big roofing burners will go upto 100kw

Any queries when you get the gear, just shout

Jason

 

[gidon]

Oh right so this is still quite weedy! I'll see how I get on.
Thanks again for your help and advice - will no doubt be "shouting" very soon!
Cheers
Gidon

 

[woodbloke]

Jason has described the various processes very well and I used to do brazing and silver soldering every week in the workshop at school. The processes aren't difficult but need a bit of practice to do well. As Jason said the critical thing is to make sure that both joining surfaces are spotless and totally grease free as even the natural oil on your skin will prevent a good joint. This sort of metal jointing always comes down to four simple things: clean metal, the correct flux, the correct heat source (and temperature) and the right joining material, in this case silver solder - Rob

 

[gidon]

Thanks Rob.

Well the torch arrived today (Sunday dispatch from Screwfix - wow!) And I picked up a can of MAPP gass from B&Q. The easy flo solder and flux will be a few days and I'm impatient so I picked up some bernzomatic "brazing rods" - called Nickel Silver Brazing Rods. As far as I can tell they must have flux built in - since their catalogue doesn't mentioned using flux for brazing. Plus they are blue on the outside!

Anyway I was eager to try it out - in 5 mins I'd created my first joint - a nut brazed to a bolt! Not very exciting I know - but you've got to start somewhere (and it's thread related!):



I've tried getting this nut off and it's impossible so well pleased.

This brazing rod's thick though 4mm odd - so guess it'll be even easier with 1.5mm easyflo stuff? Plus the finished joint looks a little messy - applying flux seperately I guess will make things neater?

It is tricky working out where and how to do this - that flame is fierce. You can see my current setup isn't ideal. Think I will try and size some fire bricks as suggested. But you still generally have to hold things in place - and I'm guessing a vice like this will conduct away a lot of the heat? So what's your holding setups? Do I wait until it's really glowing red or just starts to go red? Finally I tried joining some thin saw blade steel to a nut (!) - of course the thin bit went red hot very quickly but the nut took longer - does that matter - ie is the thin bit gettting too hot?

First impressions with my non-ideal setup is that for £30 I've added a new dimension to what I can achieve in the shed and would recommend it to anyone. My next goal is a small router plane from an allen key I've seen here or somewhere ... .

Thanks again for the advice and help.

Cheers

Gidon

 

[jasonB]

The easiest way to ensure you have a good joint is to check that the solder has flowed round the thread and can be seen under the nut. It is possible that you have just melted some solder on the top.

The blue coating is the flux. The work will still look messy after using the easyflow but once cool scrub the work under a hot tap as this will disolve any flux residue. On a small job like that it is sometimes easier to place a small (5mm long) piece of solder into the flux and then apply the heat, saves melting away half your stick of solder if you get it in the flame.

A few bits of thermalite block will also do as a hearth, if working on a metal surface try to raise the work up from it on a few offcuts of metal to reduce the heat sink effect. Parts can be held with steel wire or a pair of toolmakers clamps, I have a couple I keep just for soldering.

If working with different sized components try to apply the heat to the largest one. Getting steel very hot is not too much of a problem but you may find something like brass will distort as it melts at a closer temp to the solder, it's happened to me. The only other problem is that you will get a build up of carbon on the smaller part as you continue to heat the bigger one.

Jason

 

[gidon]

Thanks a lot Jason.
I'll try and get some thermalite blocks at B&Q then.
Cheers
Gidon

 

[dickm]

Have never tried using thermalite blocks as a hearth, but one cautionary tale. My Father was doing a job like this, put the blowlamp down without noticing it was playing directly on to the surface of a housebrick. Which produced a quite sharp explosion about a minute later, when a circular patch of brick about quarter inch thick blew out of the surface where the flame had been.
So be a bit careful where you put the torch down!

One reason why I go for firebrick

 

[DaveL]

If you use any blocks as a hearth, do not leave then outside, if they get damp they will burst when heated as the water boils inside them. DAMHIKT

 

[gidon]

Well realised I have not idea what Thermalite blocks are! Are they those normal grey blocks? Can you get fire bricks from building merchants? Chronis sell insulating bricks but they are pricey. Maybe it's only important for bigger jobs ...
Had heard that about normal bricks Dave but not sure if it's true or not for fire bricks?
Cheers
Gidon

 

[jasonB]

Thermalite is just a make that is used to describe airated concrete blocks, they are the lightgrey/white ones that look like Aero chocolate. If kept dry they won't pop. One 100mm block will probably do you, use an old handsaw to cut three 2" slices off the end, these will make a back & two sides to stand on the remaining piece of block.

The insulating bricks are better but not needed for the small amount you are likely to do.

Jason

 

[gidon]

Thanks Jason - wish I'd read this before! I just picked up some fire bricks from the local fire shop - they weren't cheap (£4 each - got 4). Do you know if these need to be kept dry and if they would be similiar to those insulating bricks?
Cheers
Gidon

 

[jasonB]

Sorry went out early this morning on a job a bit further away than usual so didn't look in until lunchtime.

Keep them dry.

Fireplace bricks are really just bricks that will not deteriorate in high temperatures. The insulating bricks stop some of the heat being drawn away and even reflect some of it back.

Jason

 

[gidon]

Jason - no worries at all! Really appreciate all your help. Think these fire bricks will do me for now even if they were a bit pricey - means I can try some brazing in the shed.
Looks like that stuff (Nickel Silver rods) I picked up from B&Q is actually bronze! So reckon it'll be easier when this easy-flo stuff arrives from Chronis. By the way I ordered the stuff with cadmium but notice you can get silver-flo 55 which is pretty much the same but without cadmium - have you tried this?
Was having a look at your site - very inspiring stuff! My wife walked by and was equally impressed. Is that all done with silver solder?
Cheers
Gidon

 

[jasonB]

I,ve not used the 55 but have used the higher melting point Silverflo24 when fabricating items that need more than one heat, it's not as easy to use as the Easyflow2 but that may be more to do with temp requirements than the lack of Cadmium.

I must confess to having the boiler for the Fowler traction engine professionally made but it is all held together with silver solder. A lot of the smaller parts are silver soldered, I have just made up three oil boxes which were used as a holder to feed oil to bearings, these are 1/2" square with a hinged top, soldered on the hinge lugs which are only 3/32" dia and take a 1/32" pin.

The hit & miss engine was fabricated using both carbon arc brazing, silver soldering and soft soldering, the only castings are the flywheels.

Jason

PS have a look at this guys site to see what he can fabricate using brass and silver solder.

 

[CHJ]

Just got back from Germany, glad you got the article gidon, had to leave before I knew whether you had received them.

 

[gidon]

Chas hope you had a good trip - thanks again.
Jason - he makes it look very easy! I'll try the easy-flo 2 stuff first and see if get any acute headaches .
Cheers
Gidon

 

[CHJ]

gidon, as long as you are not working in a confined space and for several hours at a time I doubt the cadmium exposure is of any significance. In the days before we knew better we used the stuff continually with normal workshop extraction, for most home projects your exposure is just for a few seconds as the rod melts and only then if you deliberately place yourself in a position to inhale the flux and other fumes coming off the hot part in the first place.

Edit: The trip was fine thanks, if you can envision trying to keep up with a whole family group making the most of what I think is the biggest theme park in Europe. you might know how I feel at the moment. :lol:

 

[gidon]

OK thanks Chas - I'll probably try and do it outside if I can.
Guess you need a holiday now !
FYI - found out from someone at Bernzomatic that MAPP gas will be no more soon - there's only one company who manufacturer it and they won't be soon. Will be replaced by MAP Pro which is mainly propylene. Not sure what this will mean but thought it may be of interest.
Cheers
Gidon

 

[Losos]

Jason has got it exactly right but if this is just a one off buy a tube of metal weld glue or Plastic Padding. Super glue is only good to stop the nut vibrating loose and I would guess Studlock is for the same.
John

I agree with John, the procedure Jason describes is 100% correct but time consuming, for a 'one off' I would strongly recommend an epoxy resin glue (Both metal weld & Plastic Padding are IIRC epoxies)

IMO Super glue & Studlaock are for 'anti vibration' applications.

I have had to 'lock' a nut onto studding a few times and have found a good epoxy works well. Of course if the application is critical (ie it must not come loose under any circumstances) then pinning is the only suitable method.