Scalefour Forum

True enough Philip, but if my memory is on target I believe George had his life shortened by the effects of exposure to the fumes.
Rgds

I didn’t know that, Keith. I always assumed it was the cigarettes. But then I guess George didn’t know about the fumes either. Strange that such a lovely smell (the old Mek-Pak) had such unfortunate consequences.

Philip

A litre bottle of MEK was going to be a good deal at price less than £10.00, I thought. Meet most of my plastic welding requirements till I turn up my toes, I thought.

Well, I dare say it is entirely satisfactory for welding plastic chairs to ply sleepers, and I am glad that some have obviously found it suitable for this purpose.

However... If you are contemplating such a purchase with a view to welding sheets of plastic together, here is a cautionary photograph: This is a sheet of .030" Plastikard welded with such MEK to a .020" sheet of SE Finecast embossed brick, and the extent of the distortion is readily apparent. This is the outer leaf of a wall before application of a stand-off matrix and the inner leaf. Frequently the addition of these is effective to cure minor distortions in the outer leaf, but in this case the degree of warping was too great, and I was obliged to start over, having first bitten the bullet and splashed out on a half litre can of Slaters MEK-pak, which, I am told, consists of "halogenated aliphatic
hydrocarbon" in its current incarnation. I have no connection with Slaters other than as a customer, but decided that this was a case in which I was more likely to get acceptable results with their sheet material if I used their own proprietary brand of solvent to weld it. And I did. Serves me right for having been a cheapskate with the first attempt.

Solvents seem to be something of which you need several varieties in your armoury, different plastics being susceptible to some more than others. This thread has been good at providing some useful pointers, but I would very much like to see a comprehensive and authoritative table that covers most/all of the solvents readily available, naming their constituents, concentration (where this affects how aggressive each is, and a range of concentrations is available), and effectiveness as a solvent upon a range of plastics in common modelmaking use.

Some years ago I bought a can of Mek-Pak, opened it and decanted a little into a small glass bottle I keep on the bench in a holder. Actually it is an original Slaters bottle from about 1966, but the contents remaining in the can turned brown as the can went rusty inside. Slaters were very kind in replacing it (I kept the contents at their suggestion, because it still worked even if it was brown), but I found out later that it might have been that once opened, exposure to the air started the corrosion process. So ever since I have poured the bulk supply from a can into a brown medicine bottle which seems to have solved the problem.

Philip

John Palmer wrote:A litre bottle of MEK was going to be a good deal at price less than £10.00, I thought. Meet most of my plastic welding requirements till I turn up my toes, I thought. Well, I dare say it is entirely satisfactory for welding plastic chairs to ply sleepers, and I am glad that some have obviously found it suitable for this purpose. However... If you are contemplating such a purchase with a view to welding sheets of plastic together, here is a cautionary photograph

You must have been unlucky with the type you bought. I've used the MEK I bought on ebay for lots of thing as well as tracklaying, eg the station building that I'm currently working on intermittently (see photo below) plus the platform, all using Plasticard or one of its variants and Slaters embossed sheet. The plasticard is maybe a bit thicker than what you used, but in case all turned out well and I've had no problems with it. However, as you say, there currently seems little way of knowing what the MEK you buy will or won't do.

Not making any recommendations, but in the very early days (45 years ago), with no local model shops, and unable to attend the big shows where traders were, I used cellulose thinners from Halfords to weld plasticard. It worked, if not as well as the butanone I use now. I think the point is that anything which can dissolve the material will work, and only experiment will tell, for technological dunces such as me, what is best
Speaking of risk, I used, when soldering, to have the flux in a wee jar in front of me, and my Laphroaig in a wee glass in front of me. How often did I dip the brush in the whisky...…… Nothing teaches like experience.

Allan F

allanferguson wrote:Not making any recommendations, but in the very early days (45 years ago), with no local model shops, and unable to attend the big shows where traders were, I used cellulose thinners from Halfords to weld plasticard. It worked, if not as well as the butanone I use now. I think the point is that anything which can dissolve the material will work, and only experiment will tell, for technological dunces such as me, what is best
Speaking of risk, I used, when soldering, to have the flux in a wee jar in front of me, and my Laphroaig in a wee glass in front of me. How often did I dip the brush in the whisky...…… Nothing teaches like experience.

Allan F

A problem for us all! The charming Dutch lady from whom I receive water-colour lessons and occasional refreshments now knows to place my coffee as far away as possible from the water-pot (even if it only delays the inevitable happening ...).

Gentlefolk,

Well, now that the temperatures have returned to somewhere near normal (warm and not a blast furnace!) I've managed to have an hour or so through the day testing my track laying skills having taken on board the thoughts of you good peoples. Pleased to announce to one and all that I've managed to lay a bit of track and not glue any fingers to the board!

Quick picture to show how things are progressing (-ish!)



As it's a just a straight piece of track I just started at one end and glued one rail from end to end. Chosen method was to use a glass pipette to drop some glue onto sleeper adjacent to the chair fixing in blocks of 6-8. Interesting to see that the flow was better from one side than the other (i.e. less glue on to chair from one side!). Rail was fixed In about ten minutes, and to aid geometry, I found that a steel rule sat from board to running side of rail head quite well,

Next up was to gauge and set the other rail. I opted for same process in blocks of about six sleepers and used the triangular Scalefour gauge. It seemed to take a little longer as you have to let the six sleepers completely set before moving the gauge along, so next step is to buy a couple more gauges to speed up the process.

Finally, used a set of wheels (haven't built first vehicle yet!) to check gauge, which was fine.

Next stage is to finish the track and then, as suggested, have a dabble at ballasting, happy days!