best metal to metal glue

[Wideboy]

what do you use?

tried a few 12hr epoxys in the past but they always eventually let go. Thinking of trying gorilla glue?

[tigersaw]

I keep hearing about JB weld but I've never seen any

You can get it on ebay or amazon it seems

[Wideboy]

cheers, just purchased some so shall give that a whirl

[DJ123]

What metals are you trying to glue together?

[embee]

Surface preparation is critical. What metals, what environment, what sort of loads etc? Basically, what is it you want to do?

Glues tend not to be good in "peel" situations, and not so good in straight tension. Work best in shear.

[Wideboy]

glueing RE magnets to brake discs so its going to be under some force. The last resin i used (can't remember the name, it was industrial grade) lasted a long time but it still stayed elasticy/rubbery (if that makes sense) so it was inevitably going to let go.

just for reference i can't screw in the magnets like they're suppose to be as they're not OEM disc's, the spacings would be wrong.

[Specialone]

Stick or mig weld?

[embee]

JB Weld is basically just an epoxy filled with aluminium powder, good stuff but in principle no better than a straight epoxy. Slow setting ones generally end up stronger.

If it doesn't set hard there's something not right, wrong mix, not enough or too much hardener etc.

Surface prep is the critical thing. I'd use brand new fairly coarse abrasive paper immediately before applying the glue to ensure completely clean scratches for the glue to key onto. I'd lightly clamp them together, but not so that all the glue is squeezed out. Keep it warm but not hot to cure.

Is there no way you can drill the disc and fit round magnets in with a high grade Loctite, a retainer or bearing fit grade like 638 or similar? A much more secure arrangement.

[Pete7]

Don't forget epoxy resins are softened by heat and break down in sunshine but if your last attempt was soft then as Embee says there was something wrong. Araldite is used to repair Army helicopers, but the packet goes in the disposal locker straight afterwards so an old opened packet isn't used ever again on flying machines. Okay on landrovers though.

Pete

[Wideboy]

its wasn't completely rubbery, it was a new packet and mixed properly but it must of broken down, off the top of my head it had been on there for 2 year, it also set a pale dark green in colour. All the others are still on so it must of been a bad surface under it.

i'll give it another go in the week and make sure its clean and keyed up

[Specialone]

Still think you should weld it instead Gav.

[suzukigt380paul]

top quaility super glue might work,something like powerbond 806

[Wideboy]

Still think you should weld it instead Gav.

The heat would probably warp the rotors. I've not heard of anyone welding them before? :confused:

I would have thought superglue would be too brittle?

[andrewsmith]

Hall effect sensor Gav?
Ask biblo how he attached the magnets on the rear sprocket

I would be of the notion to drill the disc and bolt on

[Fallout]

I've used JB Weld for a few things. Don't recall it ever breaking under any uses. It's the strongest glue my inexperienced brain has heard of.

[Wideboy]

I don't think it would be wise to drill holes into something that only has about about 6mm wide span. Plus I don't particularly want to be drilling holes in my rotors :lol:

I might try silver solder if this jb weld doesn't work. I'll pm bib

[Pete7]

I might try silver solder if this jb weld doesn't work. I'll pm bib

Wouldn't the heat trash the magnet as it alters the crystaline structure of the steel?

[Wideboy]

I wouldn't think it would get hot enough? I'll give this jb weld a go

[Spank86]

Chemical metal?

[Fallout]

As discussed gav, Pritt Stick or those nuggets we were talking about.

[dizzyblonde]

Heavy metal :clown:

[Mark_h]

Find out what Suzuki put on the front mudguard bolts and use that. It seems you need to add some rainwater and road salt to cure it but once cured it is an amazingly permanent joint. It's slightly fluffy white stuff.

[andrewsmith]

I might try silver solder if this jb weld doesn't work. I'll pm bib

Silver should work, it needs done with Oxycet for best effect.
That should work as I've witnessed commission silver solder be pressure tested to 30bar

[Spank86]

It's slightly fluffy white stuff.
Aluminium oxide.:D

[Mark_h]

Wideboy, sounds like we've got it sorted. Drill a few holes in your rotor then fix them in with aluminium oxide. Sounds like a well thought out plan with no scope for catastrophic failure of any useful part of your motorcycle. PS, if you give it a go can I have your Thunderace?

[andrewsmith]

Aluminium oxide.:D

*******ing pain in the **** you mean!

[Wideboy]

I was going to drill speed holes all over the thunderace

[Spank86]

put a few in the petrol tank!


that'll shed some weight.

[Wideboy]

With how I rode it last time it might as well.

25quid puff and its gone

[yorkie_chris]

Silver should work, it needs done with Oxycet for best effect.
That should work as I've witnessed commission silver solder be pressure tested to 30bar

It depends entirely on the joint.

Plus what do you think happens to neodymium magnets under an oxyacet flame?
And the rotor carrier is probably ally, which is a **** to do.


I'd try rather than drilling holes, to counterbore some holes not all the way through the ally and loctite them in.


That is of course if the simple method of bolting them into the rotor holes doesn't work.

You could also pick up off the rivets or bolts directly and use a speedohealer to sort it out.

[Fallout]

Did a google and it looks like there is actually a magnetic paint product. Could be worth experimenting to see if that'd work as a pick up.

[Specialone]

The heat would probably warp the rotors. I've not heard of anyone welding them before? :confused:

I would have thought superglue would be too brittle?

Sorry Gav, i was winding you up and being silly :nomore:

[keith_d]

No point trying welding, silver solder or brazing on Neodymium magnets. Their Curie temperature is only around 400C so they'll be fubar.

Best bet is to drill an interference fit hole, then shrink fit the magnet. Put the disk in the oven at around 200C for half an hour and the magnet assembly in some freon (pipe freezer) or better still liquid nitrogen. Pop the chilled magnet into the hole then let it warm up and expand

If you've already got a precision fitting hole consider making the hole a little deeper than the magnet, drop the magnet in then burr over the edges of the hole with a ball pein hammer. It's not pretty but it'll do the job.

Just my thoughts,

Keith.

P.S. Rare earth magnets are quite brittle, so hammering them into a hole isn't a great plan.

[yorkie_chris]

Or just bolt them into the rivets which takes seconds and doesn't weaken anything :)

You also don't need extreme cold to do an interference fit. Ally expands lots and makes it easy but the hard part is drilling accurate enough holes.

Personally I'd shy away from weakening the carriers unless I'd exhausted absolutely every other option.

[keith_d]

You also don't need extreme cold to do an interference fit. Ally expands lots and makes it easy but the hard part is drilling accurate enough holes.



Yep, it's easier to turn the piece you're inserting to match the hole, assuming you have that option. For short runs in aluminium you can also make a one-off reamer. Drill the next smaller size, then ream to fit.

Finally, there is a dirty trick involving lapping down a spiral mill cutter (with a split lap) so that it's a couple of thou under size. Then using it to ream out the hole. Just be sure you lock it up afterwards so nobody tries using it!!

[yorkie_chris]

Alternatively you could just use 20p worth of M3 nuts and bolts to fit them through the disc rivets...

[phil24_7]

glueing RE magnets to brake discs so its going to be under some force. The last resin i used (can't remember the name, it was industrial grade) lasted a long time but it still stayed elasticy/rubbery (if that makes sense) so it was inevitably going to let go.

just for reference i can't screw in the magnets like they're suppose to be as they're not OEM disc's, the spacings would be wrong.

I JB welded my speedo magnets on 3 years ago and they are still there. The magnets are glued into holders and the holders are bolted onto the disc.

[Nobbylad]

Alternatively you could just use 20p worth of M3 nuts and bolts to fit them through the disc rivets...

Like you do for a Gixer front end speedo conversion

[dirtydog]

No point suggesting fitting the magnets into the rivets because...



just for reference i can't screw in the magnets like they're suppose to be as they're not OEM disc's, the spacings would be wrong.

[phil24_7]

The spacing aren't going to affect things too much once your moving at 20 or 30 mph.

[BanannaMan]

I JB welded my speedo magnets on 3 years ago and they are still there. The magnets are glued into holders and the holders are bolted onto the disc.





:winner:
Works a treat, looks tidy and can be had for cheap.
What more could one ask for?












(why does that strangely sound like everything I want in a woman?) :smt017

[Wideboy]

Some more magnets arrived last night, replaced the missing one with jb weld and I'll wait for the others to come off by themselves rather that force them off.

Interestingly they're that strong you'd think they'd stick to something when they come off