'Ungluing' a whitemetal locomotive

[LNWRNORM]

Hello all,

 

I have a whitemetal locomotive, that has been constructed badly with Araldite, which I wish to rescue if I can. (The kit is no longer made)

My question is therefore what is the best way to remove the araldite?

I have looked at previous answers, which appear to favour Nitromors, and which I have used it in the past to some effect.

However, the key solvent component of Nitromors has now been banned and I am told the current product is rubbish!

Is this the case?

It has also been said that cellulose thinners can work, anyone done this and been successful?

Another method involves heat (I am told), but as it is whitemetal I am a bit nervous to use the heat method, but again does this work?

 

Does anyone have any other suggestions? By the way, boiling water had no effect whatsoever.

 

Thank you

Norman

[malc125]

Have you tried a strong solution of washing power, mug full in a washing up bowl ? leave it to soak for 24 hours. It should weaken the glued joints so that they will come apart. Don't know why it works. Aso useful for removing enamal paint from plastic

[hayfield]

Norman

 

Water boils at 100 degrees, whitemetal's melting point is something like 140 or a bit more degrees.

 

Now don't let the whitemetal touch the pan bottom as this will be a lot hotter. Also larger pieces of whitemetal take longer to both heat up and cool than smaller pieces.

 

I like to dunk the pieces to be separated and leave them in for a short time, then gently try to part them. if still stuck leave in a bit longer and try again, keep increasing the time each time until they come apart. Just be patient. 

 

I think a caustic soda solution also attacks epoxy glue but leave in for 24 hours and no aluminium parts.

 

I think folk use oven cleaning foam (keep parts in plastic bag) for paint removal.

 

Sometimes parts which are not exposed are only affected by heat as the Nitromores/caustic soda does not penetrate too much

 

I think I read that its only the quick set epoxy is affected

[LNWRNORM]

Have you tried a strong solution of washing power, mug full in a washing up bowl ? leave it to soak for 24 hours. It should weaken the glued joints so that they will come apart. Don't know why it works. Aso useful for removing enamal paint from plastic

 

No, I have not. Thats one to try tomorrow - Thanks

[EddieB]

Sorry to state the obvious, but always wear rubber gloves when handling Nitromors or caustic soda (sodium hydroxide) solution.  If tempted to try a warm solution of caustic soda, remember to wear eye protection also.

 

The problem with removing epoxy resin glues is their resistance to almost all solvents once hardened.  Heat will soften, but the temperature would need to exceed the melting point of the white metal to have a useful effect.  DMF (Dimethylformamide) has been suggested elsewhere, but is considered carcinogenic and I'd put my health before dismantling a kit.

 

I'd certainly be tempted to try the washing powder solution first.

 

Not something I've tried, and something of a guess, but I wonder whether freezing might make the araldite become more brittle - enough to carefully separate the components, that can then be cleaned up with knives and abrasives.

[LNWRNORM]

Sorry to state the obvious, but always wear rubber gloves when handling Nitromors or caustic soda (sodium hydroxide) solution.  If tempted to try a warm solution of caustic soda, remember to wear eye protection also.

 

The problem with removing epoxy resin glues is their resistance to almost all solvents once hardened.  Heat will soften, but the temperature would need to exceed the melting point of the white metal to have a useful effect.  DMF (Dimethylformamide) has been suggested elsewhere, but is considered carcinogenic and I'd put my health before dismantling a kit.

 

I'd certainly be tempted to try the washing powder solution first.

 

Not something I've tried, and something of a guess, but I wonder whether freezing might make the araldite become more brittle - enough to carefully separate the components, that can then be cleaned up with knives and abrasives.

Hi Eddie,

Dont worry, I am long enough in the tooth to know all the safety procedures, but thanks anyway.

It also amazes me that DMF, the stuff taken out of Nitromors, can be bought on e-bay of all places with no questions asked!

Freezing is an option, as is caustic soda, but I will try the washing powder first

Cheers

Norman

[Wayne Rite]

I've been pulling whitemetal loco's apart for years, the best thing I've used is methylene chloride which I used to get through a friend of mine who was an industrial chemist, this would reduce Araldite and any paint present to a soup which could be rinsed off, but do it with the usual PPE and over a mesh strainer so you don't lose anything down the plug 'ole!

 

If its just epoxy then a bath of vinegar will in time cause the bonds to break and the residues can be removed with a fairly stiff brush, not your wifes toothbrush!

 

Cheers

[Kenton]

 

It also amazes me that DMF, the stuff taken out of Nitromors

I don't think it was DMF in Nitromors but methylene chloride. Not quite as much a carcinogen and smells quite pleasant in comparison. Methylene chloride is toxic by inhalation. This is most likely the reason for the change of formulation (the nanny state fears of solvent abuse by children) the same reason for the dumbing down of Evo/Bos stick impact adhesives.

 

I agree with Wayne above that methylene chloride is the best solution for knocking down glued whitemetal kits. Of course I am of the opinion that they should never be glued in the first place and low melt solder would always be employed. In those cases methylene chloride has no affect but a pan of boiling water gives the same result.

 

But beware methylene chloride is also toxic. It has been reported to have triggered heart failure when quite high vapour concentrations have been inhaled in confined spaces.

[34theletterbetweenB&D]

Oh for the days when I had a fully equipped lab to play in. Hot dimethylene chloride, a tuneable ultrasound bath and fume cupboard made short work of such problems. Any academics in chemistry, or industrial chemists on board prepared to offer a sideline service?

[LNWRNORM]

I've been pulling whitemetal loco's apart for years, the best thing I've used is methylene chloride which I used to get through a friend of mine who was an industrial chemist, this would reduce Araldite and any paint present to a soup which could be rinsed off, but do it with the usual PPE and over a mesh strainer so you don't lose anything down the plug 'ole!

 

If its just epoxy then a bath of vinegar will in time cause the bonds to break and the residues can be removed with a fairly stiff brush, not your wifes toothbrush!

 

Cheers

 

Hi Wayne,

Thanks for the info. I can get hold of methylene chloride no problem and I have PPE and will be outside, but how do you use the stuff?

I presume you just soak the the loco body in the solution? But for how long, and is that a complete immersion and what sort of container should I use for the soak?

Thanks

Norman

[jcm@gwr]

FWIW, I've used Nitromors (new formula) and it did a

good job of removing the epoxy (and the bits were nice

and clean as well!

 

Obviously, I don't know what quality of epoxy was used.

 

Jeff

[brack]

if it helps, epoxy resins (and cyano superglues) usually begin to debond at 65 degrees, so boiling the kettle, then pouring freshly boiled water over your loco (in a tub/pan) and letting it stand for 20 minutes or so, then repeat as necessary is the solvent/smell free approach I use. You'll then have to use a toothbrush and some sort of scraper (small screwdriver) to remove the softened glue residue.

 

Of course there are some heavier duty formulations of glues which are more heat resistant, but its unlikely that someone's sought out extra strong industrial grade stuff to cobble their kits together with.

[jcm@gwr]

 

Of course there are some heavier duty formulations of glues which are more heat resistant, but its unlikely that someones sought out extar strong industrial grade stuff to cobble their kits together with.

 

Except all those ex-chemists, etc. who made their own/got some from work for free!

 

Jeff

[45568]

Hi Wayne,

Thanks for the info. I can get hold of methylene chloride no problem and I have PPE and will be outside, but how do you use the stuff?

I presume you just soak the the loco body in the solution? But for how long, and is that a complete immersion and what sort of container should I use for the soak?

Thanks

Norman

As the 'friend' referred to by Mr.Rite, Methylene chloride has a very low boiling point and if left in an open container will very quickly 'flash off'. It is best to find a closable container with a tight seal, Tupperware, large glass jar etc., put the body in, fill with MeCl2, and put the lid back on. Reaction usually occurs within 15-30 minutes.

It helps to have an old toothbrush handy to remove stubborn traces of paint and other material. Care needs to be taken with the gloves used, lightweight polythene are best, kitchen gloves will quickly dissolve on you! Similarly, most plastics other than polythene/polypropylene are attacked by MeCl2, so choose your container with care!

Dispose of waste carefully, not down the drain.

Cheers,

Peter C.

[Quarryscapes]

Sod the chemicals, boiling water is fine, just use the same method the cooks use for melting chocolate - a bowl full of water with your kit in it floating in a pan of boiling water. Always worked for me when undoing previous botch jobs. 

 

Of course if you have paint to remove as well then maybe go straight for the nitromors...

[jimwal]

If the kit has been poorly built it is possible that the joint surfaces were never cleaned or fettled prior to assembly. I beileve epoxy needs 'laboratory clean' conditions for maximum strength.

I have successfully prized whitemetal kits apart using a narrow wood chisel or screwdriver sharpened like a chisel and have not used any solvents or water, boiling or otherwise.

 

On parting the epoxy will be stuck on one side or the other and can be seperated easily.

The epoxy waste will often reveal precise reproductions of the ill fitting joint faces of older kits.

 

Hope this helps

 

Jim

[adriank]

Sod the chemicals, boiling water is fine, just use the same method the cooks use for melting chocolate - a bowl full of water with your kit in it floating in a pan of boiling water. Always worked for me when undoing previous botch jobs. 

 

Of course if you have paint to remove as well then maybe go straight for the nitromors...

On reading this I dug  out a Wills G6 that I had partially assembled using Araldite some 40 years ago. No need for a bain marie, I just put the kit in an old margarine tub and tipped boiling water on it. After a couple of minutes, I pulled the pieces apart using tongs. I was able to peel off the remaining Araldite very cleanly and the whitemetal parts are good as new.

 

Thanks a lot for the tip. I'm well pleased.

 

Regards,

 

Adrian

[34theletterbetweenB&D]

Inevitable question, which Araldite? The five minute stuff - totally useless -  or the 24 hour curing sticketh like excrement to a manual earth moving implement?

...dimethylene chloride,...

On rereading this thread I discovered I had invented a non-existent chemical. Meant dichloromethane by IUPAC nomenclature, what was methylene dichloride, CH₂Cl₂.

 

Undoubtedly due to the brain scrambling effects of exposure to all sorts of vile substances in my youth.

"Dr Schmungus, it definitely is dissolving the platinum crucible."

"Ah so, Iss zere anyvun on zer roof near zee extract vents do you suppose?"

[LNWRNORM]

Inevitable question, which Araldite? The five minute stuff - totally useless -  or the 24 hour curing sticketh like excrement to a manual earth moving implement?

Unfortunately, I am no closer to getting this thing apart. Boiling water had no effect at all, neither did soaking in washing powder, this glue, I am assuming it is araldite, is seriously hard, a sharp screwdriver merely scratches it, and there is lots of it. Whoever put this together did not intend for it to come apart. A shame then that they did not put it together properly!

I guess I am staring at a chemical solution, or put it back in the box at the back of the shelf and move on, I have plenty of other choices and kits to be made.

I might just try the new Nitromors and see what happens.

[hayfield]

It may be the longer set epoxy, as I have heard that only the fast setting ones react to Nitromores and boiling water. But I may be wrong

[hartleymartin]

I've been told that a bath in paint stripper will do it. Prettynasty stuff tthough.

[hayfield]

Also has anyone mentioned brake fluid

[Il Grifone]

The 'proper' 24 hour Araldite is cured by heat, so boiling water is unlikely to have much effect. I found this, but 4 & 5 are not much use on white metal. The rest involve noxious chemicals!*

 

http://www.tedpella.com/technote_html/Reworking_Cured_Epoxy.pdf

 

Grinding it off with a burr in a mini-drill might produce results but care would be needed as the resin is harder than the white metal.

 

*Sulphuric acid is used for unblocking drains (very effective! it cleared our blocked kitchen drain in Italy when the usual culprits had failed), as well as car batteries.

 

Toluene used to be a component of cellulose thinners, but I think it has been replaced by something less toxic. (Cellulose thinners are themselves hard to find these days - in the UK at least, they were still on sale in Italy last time I was there.)