Plastic chairs and MEK. Very poor bond.

[AndyID]

9 hours ago, martin_wynne said:

At that time the only plastic-based bullhead track available was SMP Scaleway.

 

 

I was greatly impressed when I saw it at first although somehow it still didn't look quite right. The latter version was a lot better. I still have some of the original stuff. I'm saving it so our kids can have the pleasure of disposing of it

[Haggerleases]

Oh dear. 

After my reasonable trial results the other day, I made a length of track at the weekend. Pre-loaded the sleepers with butanone, added a decent smear of 'Poly Pipe' adhesive, put the rail with the pre-threaded chairs on the sleepers after painting a little butanone on each, more butanone on the sleeper after fitting to wick its way in, weighted it down etc. Looked great. Felt quite pleased with myself. 

Left it 12 hours or so to be safe, picked it up off the template and the thing basically fell to bits in my hand. Disaster. 

I think I'm going to have to admit defeat very soon. I need my track to be way more durable than this. my EMGS bullhead rail pulls out of the chairs very easily too.. I think I may be doing something fundamentally wrong, though I can't think what.

Back to the good old soldering iron at this rate.

 

 

 

[Joseph_Pestell]

When using solvent on pvc waste pipe, it is recommended that one sands the surface of the areas to be joined to ensure a good joint.

 

I imagine that the same would be true of ABS chairs. Best done when still on the sprue.

 

I recall problems (many years ago) with MEK and ABS. I had built a rather complicated skew bridge. All seemed well at first but as the MEK dried out, not having bonded to the ABS, the whole thing fell apart.

[martin_wynne]

45 minutes ago, Haggerleases said:

added a decent smear of 'Poly Pipe' adhesive, put the rail with the pre-threaded chairs on the sleepers

 

Hi,

 

Did you miss a step there? "added a decent smear of 'Poly Pipe' adhesive, waited a good hour for the Polypipe to dry, put the rail with the pre-threaded chairs on the sleepers"

 

The idea is that the Polypipe impregnates the sleeper with a plastic material. It's not going to do that if you wash it out again by flooding butanone over it while it is still wet.

 

In the original Exactoscale days, whole batches of sleepers would be Polypiped in advance, and left for days before being used. Some folks who cut their own plywood timbers would Polypipe the sheet of ply before sawing it up.

 

You can make your own Polypipe by chopping up scraps of plasticard, chair sprues, etc., and dissolving them in butanone. It might work better than real Polypipe because you can adjust the consistency by trial and error to whatever works best.

 

If it still doesn't work after all that I would begin to wonder if your "butanone" is in fact butanone? What happens if you brush it over the chair sprues? They should go instantly soft , sticky and smeary, and the brown colour should come off on your fingers.

 

cheers,

 

Martin.

[Neil]

Sorry I'm late to the thread. I built a lot of the track on my previous layout Morfa using C&L chairs and ply sleepers stained with a water based ink.

 

 

I used EMA Plastic Weld to stick the chairs to the sleepers without any need to treat the sleepers with polypipe or any other adhesive. I had no problems with the bond even though the layout room (in an old stone chapel) could get pretty arctic in winter. I couldn't ping chairs off with my finger but I could loosen the bond with a sharp craft knife which was useful when it came to making adjustments.

[martin_wynne]

35 minutes ago, Neil said:

I used EMA Plastic Weld

 

That's dichloromethane, not butanone.

 

I've been wondering whether the advice to use butanone for ABS is only good for plastic-to-plastic bonds? It has to be a very pure grade to be effective. Dichloromethane is better, but it's a very nasty chemical:

 

Toxicity

Even though DCM is the least toxic of the simple chlorohydrocarbons, it has serious health risks. Its high volatility makes it an acute inhalation hazard. It can also be absorbed through the skin. Symptoms of acute overexposure to dichloromethane via inhalation include difficulty concentrating, dizziness, fatigue, nausea, headaches, numbness, weakness, and irritation of the upper respiratory tract and eyes. More severe consequences can include suffocation, loss of consciousness, coma, and death. DCM is also metabolized by the body to carbon monoxide potentially leading to carbon monoxide poisoning. Acute exposure by inhalation has resulted in optic neuropathy and hepatitis. Prolonged skin contact can result in DCM dissolving some of the fatty tissues in skin, resulting in skin irritation or chemical burns.

 

Not to mention the utterly awful pong.

 

Don't use it to make your own Polypipe mixes.

 

Take care.

 

Martin.

Edited July 26, 2021 by martin_wynne
quote added

[Izzy]

 

I’m sorry that things just don’t seem to be working out for you no matter what you try. I have no experience of Exactoscale chairs, but while it doesn’t seem logical I get the distinct feeling that they are the core problem somehow. That the material they are moulded from, and there can be an almost infinite number of plastic mix combinations, just won’t play nicely with the available glues you have tried. It is noticeable that most people who have stated no issues with using plastic chairs on ply sleepers whatever the liquid glue used appear to have used C&L ones.

 

As I have stated previously I have always used Slaters Mek-Pak even though the present day offering is no longer based on the chemical MEK. I have read on a thread here somewhere from Dave Hunt that this was because they found George Slater collapsed in the works one day having been overcome by the noxious fumes, and so changed the formula to something less dangerous to peoples health. I have also used both PlasticWeld and pure Butonone but they are both much more aggressive in action and can severely melt chair surfaces with over-application, bolt detail etc.

 

To further illustrate that using C&L chairs seems to cause no problems even using the current MEK-PAK here are a few shots of my current 7mm micro-minimal plank that uses – don’t laugh – plastic chairs on sleepers cut from mountboard. Again using Mek-Pak. So this is good enough to melt the chair base to allow it to adhere to almost any material.

 

 

 

 

You will note that as it was 7mm I used PCB strip under the crossing nose and at the divergence for electrical connections and a bit of added strength. In 4mm/P4 I have always used a few rivets in these locations. Here is my most recent P4 plank track build. Again using C&L on ply.

 

 

 

 

I only ever use very thin strips of d/s tape to hold the sleepers in place on a template, and it is ‘peeled’ off using turps/white spirit washed on to temporarily break the glue joint.

 

 

On it’s own trackwork made in this manner is fairly fragile until laid down. Painting the rail sides and chairs to ‘lock’ them together can be done before removing from a template. It does often help.

 

It should be noted that quite a few modellers build their track straight onto the baseboard. This does overcome the issue of lifting the finished track from the template. I never have, preferring to build it on the workbench, but it’s each to their own.

 

However, once laid and finished unless a scalpel is used to break the joint between chair and sleeper I find it impossible to part them without extreme force. And the older the construction the more force seems needed. That the bond strength increases with age. A screwdriver under the rail levered up will do it, but wrecks both the rail and the chairs, which on average break in two, one half coming away but the other staying firmly anchored to the sleeper. Very rarely do chairs come away whole. If they do often they take the top ply surface with them.

 

Might I suggest that you acquired some C&L chairs to see if your experience is the same as with the Exactoscale ones. Please don't give up, the results are worth the effort I feel.

 

 

 

 

 

Edited April 3, 2022 by Izzy

[Haggerleases]

Izzy. Thanks so much for that comprehensive reply. I appreciate your effort. I was starting to think it was the composition of the chairs, so you may very well be right. I am going to get hold of some c&l chairs and see if they work any better. I guess if I don't figure out the issue I'll always wonder what caused it. 

Hand in pocket again lol. 

[martin_wynne]

@Haggerleases

 

Hi,

 

As an aside, have you seen the 3D Plug Track which I'm working on in Templot? This is EM:

 

 

 

 

3D printed chairs are a press fit into "sockets" in the timbers. Which could be 3D printed as above, or several firms offer laser cutting of plywood track bases from Templot files. The socket is just a simple rectangular aperture.

 

No glue, no solder, no gauges needed.

 

It is all still being developed, but there is enough in the latest Templot release to do plain track. In any gauge or scale or radius.

 

More info: https://85a.uk/templot/club/index.php?threads/3d-printing-plug-track-from-228a.229/

 

p.s. the bottom side-flange on the 3D printed sleepers is intended to be hidden in the ballast. It strengthens the sleepers alongside the sockets.

 

cheers,

 

Martin.

Edited July 26, 2021 by martin_wynne
p.s. added

[5050]

I've used Butanone to stick C&L chairs to all sorts of substrates including card, foamboard, wood.  No problems at all.  No need to 'prime' with anything.

[martin_wynne]

1 hour ago, 5050 said:

I've used Butanone to stick C&L chairs to all sorts of substrates

 

The OP on this topic is trying to stick Exactoscale chairs. We don't know that it is the same polymer as C&L chairs.

 

Martin.

[hayfield]

4 minutes ago, martin_wynne said:

 

The OP on this topic is trying to stick Exactoscale chairs. We don't know that it is the same polymer as C&L chairs.

 

Martin.

 

 

I have never known any issues with Exactoscale chairs and I use both C&L and Exactoscale chairs in equal measures. However Phil at C&L told me because of the compounds of the plastic used, Butanone is the best and recommended product to use. Though with plastic to plastic I have used other makes,

 

I have found when using Butanone with ply timbers the best results are when you flood the joint with solvent 

[5050]

46 minutes ago, martin_wynne said:

 

The OP on this topic is trying to stick Exactoscale chairs. We don't know that it is the same polymer as C&L chairs.

 

Martin.

I know Martin, just following on from other posts relating sticking to substrates other than ply sleepers.  I've also used the same methods with Exactoscale items.

[martin_wynne]

42 minutes ago, 5050 said:

I know Martin, just following on from other posts relating sticking to substrates other than ply sleepers.  I've also used the same methods with Exactoscale items.

 

The problem is that the OP's Exactoscale chairs won't stick with his butanone.

 

Since no-one else reports a similar problem, either his Exactoscale chairs are a different polymer, or his butanone isn't butanone.

 

I'm leaning towards the conclusion that there may be significant difference in the performance between industrial grade butanone and 100% laboratory grade.

 

Martin.

[NCB]

On 26/07/2021 at 13:13, martin_wynne said:

 

That's dichloromethane, not butanone.

 

I've been wondering whether the advice to use butanone for ABS is only good for plastic-to-plastic bonds? It has to be a very pure grade to be effective. Dichloromethane is better, but it's a very nasty chemical:

 

Toxicity

Even though DCM is the least toxic of the simple chlorohydrocarbons, it has serious health risks. Its high volatility makes it an acute inhalation hazard. It can also be absorbed through the skin. Symptoms of acute overexposure to dichloromethane via inhalation include difficulty concentrating, dizziness, fatigue, nausea, headaches, numbness, weakness, and irritation of the upper respiratory tract and eyes. More severe consequences can include suffocation, loss of consciousness, coma, and death. DCM is also metabolized by the body to carbon monoxide potentially leading to carbon monoxide poisoning. Acute exposure by inhalation has resulted in optic neuropathy and hepatitis. Prolonged skin contact can result in DCM dissolving some of the fatty tissues in skin, resulting in skin irritation or chemical burns.

 

Not to mention the utterly awful pong.

 

Don't use it to make your own Polypipe mixes.

 

Take care.

 

Martin.

 

I quite like the smell of Plastic Weld. In fact I use it in preference to other stuff wherever I can for that reason

 

However, I do use it in quite limited sessions and don't hang around in the same room afterwards.

 

Nigel

[martin_wynne]

On 30/07/2021 at 15:09, martin_wynne said:

Since no-one else reports a similar problem, either his Exactoscale chairs are a different polymer, or his butanone isn't butanone.

 

Returning to this topic to mention that it is possible to purchase Butanol (Butyl Alcohol) on ebay -- which is NOT Butanone:

 

 https://www.ebay.co.uk/itm/141916409397

 

If someone has problems getting chairs to stick, maybe they have the wrong one?

 

Martin.

[Stephen Freeman]

I use real MEK which is Butanone as I understand it - Methyl Ethyl Ketone

Edited October 28, 2021 by Stephen Freeman
addition

[hayfield]

6 hours ago, Stephen Freeman said:

I use real MEK which is Butanone as I understand it - Methyl Ethyl Ketone

 

Stephen

 

The trouble is some confuse a similar named brand which now is not the same, and will not perform as well

 

I have recently fitted some wall panels on to tiles, I bought the brand of adhesive recommended by the panel manufacturer, and followed their installation instructions

 

Now with C&L chairs Phil recommends Butanone, if someone wishes to complain about another brand of solvent not working, they should have followed C&L's instructions

 

Secondly be careful of not using dye which may contain a substance which affects adhesion. Worth doing a test first, or apply the colouring after the chairs have been fitted

 

I use a spirit based stain (not dye) and have had no issues to date

[Stephen Freeman]

For the sake of clarity I use Methyl Ethyl Ketone.

[57xx]

On 15/07/2021 at 01:41, dpgibbons said:

Polypipe solvent C250 is 50%-100% butanone

 

On 15/07/2021 at 06:25, martin_wynne said:

 

I believe it is a cement rather than a pure solvent, i.e. it has some ABS or other filler dissolved in it. Which becomes embedded in the plywood has it dries. To which the chairs can then be bonded.

 

On 23/07/2021 at 10:59, martin_wynne said:

p.s. Talking of misinformation, my apologies. I think it may be PVC filler in the Polypipe cement, not ABS as I said. Or maybe both.

 

All the info is in the SDS.

[Haggerleases]

Still struggling! Exactoscale chairs with MEK/Butanone onto ply is a seriously poor bond. I've tried everything, every permutation, and I can still flick them off the ply with very little effort. Perhaps I'm being over ambitious. I want track I can still use daily in 40 years. I feel like I shouldn't give up though, the track sections look amazing, just so damn fragile! 

[martin_wynne]

58 minutes ago, Haggerleases said:

Still struggling! Exactoscale chairs with MEK/Butanone onto ply is a seriously poor bond. I've tried everything, every permutation, and I can still flick them off the ply with very little effort. Perhaps I'm being over ambitious. I want track I can still use daily in 40 years. I feel like I shouldn't give up though, the track sections look amazing, just so damn fragile! 

 

Are you quite sure it is 100% laboratory-grade Butanone?

i.e.

NOT Butanol.

NOT industrial-grade Butanone.

 

Where did you get it from?

 

What about the plywood? Has it been treated with something to prevent liquids from penetrating the surface? Does it have a very close-grained hardwood surface skin? Where did you get it from?

 

There has to be an explanation because many other modellers have been using the system successfully for years. But it is never going to be bomb-proof -- chairs can always be removed from plywood using a knife blade under them. For a rock-solid build you need to use plastic timbers.

 

cheers,

 

Martin.

Edited April 12, 2022 by martin_wynne
typo

[hayfield]

14 hours ago, martin_wynne said:

 

Are you quite sure it is 100% laboratory-grade Butanone?

i.e.

NOT Butanol.

NOT industrial-grade Butanone.

 

Where did you get it from?

 

What about the plywood? Has it been treated with something to prevent liquids from penetrating the surface? Does it have a very close-grained hardwood surface skin? Where did you get it from?

 

There has to be an explanation because many other modellers have been using the system successfully for years. But it is never going to be bomb-proof -- chairs can always be removed from plywood using a knife blade under them. For a rock-solid build you need to use plastic timbers.

 

cheers,

 

Martin.

 

 

I have heard that some dyes contain wax, not sure if this is the problem here but worth a warning, I use a spirit based dye, which I allow to dry out thoroughly before use

[OFFTHE RAILS]

A very interesting thread but as a retired chemist I should point out that Butanone and Methyl Ethyl Ketone (MEK) are just earlier common names for what is Butan-2-one -  the modern systematic name for this compound.

Mek Pak is just a trade name for a proprietary solvent and the Slaters version  on offer today says on the label,  "contains halogenated aliphatic hydrocarbon". This means the chemical contains chlorine and is definitely not Butanone aka Methyl Ethyl Ketone aka Butan-2-one. (also aka Ethyl Methyl Ketone according to wikipedia.)

Ian

 

[fulton]

Most of my trackwork is plastic based, but I have a timber viaduct where I used super glue to fix C&L plastic chairs to lime wood bulk timbers, the rail will pull out of the chairs before the glue joint fails, is there a problem using super glue?