I hauled out a Walthers Proto SD9 (920-41622) to run at our club last night. I discovered that one of the stanchions supporting the right forward (short hood) handrail had broken a bit down from the top. Because of their flexibility, I think these are delrin. Is there a reasonable and functional repair without having to replace the entire part? I'm skeptical that a simple drop of AC will really do the job.
John
There are epoxies out there that are made for Delrin. They are not on the hobby short list of adhesives. As Delrin is a thermoplastic you can melt it with a soldering iron. Use a tip that doesn't have solder on it and practice a lot before going after a handrail. Did I mention you need to practice a lot ??
Lee
Lee 1234There are epoxies out there that are made for Delrin. They are not on the hobby short list of adhesives.
LePage offers a "SuperGlue" that works with such plastics. It comes with an "activator" that looks like a small marker-pen...rub it onto both of the surfaces to be joined and allow 60 seconds for it to dry, then apply the ca sparingly to only one of the surfaces to be joined, then press the parts together and hold for 30 seconds.
The activator will outlast the small amount of ca that's part of the package, but will also work with other brands of ca.I've had mixed results using it, but for such a small item, I'd likely drill (very slightly) the two surfaces to be mated, then use a suitably-sized piece of wire to re-enforce the joint. I must admit that in most cases, I'm not a fan of Delrin for handrails, grabirons or sill-steps, especially where the fit is sloppy.
Wayne
Yes I prefer small diameter brass wire.
I've successfully used small amounts of CA to hold the staunchions or handrails in place, then supplemented the joint with "MEK Substitute" found at the big box stores. Several appliacations of MEK. The MEK will tend to run down the staunchion and mar the paint, so keeping the stauchion horizontal would help control the application.
- Douglas
Methyl Ethyl Ketone?
philo426 Methyl Ethyl Ketone?
Must be a know known carcinogen!
For years, I used lacquer thinner for gluing everything that I built using styrene, but when the powers that be decided to make it ''less dangerous", it became useless as glue, but still worked well for thinning lacquer-based paints.
After reading on this Forum about MEK as a glue, I found a source for it, and it works reasonably well, but does evapourate much faster than the old-style lacquer thinner. A couple years ago, I found, at the same supplier, a correct version (unadulterated) of lacquer thinner, and it works as well as the original version did.
The source for this stuff is from a supplier which supplies various other businesses, so I did get a bit of questioning on why I was buying what was potentially dangerous substances, but after explaining what I was using it for, I can drop by anytime, if I need to pick-up more.When I was using large quantities of it, I worked in my shop, about 100' behind the house, in a 180 year old house, now a garage, and in that atmoshere, always wore a two stage respirator. The main time that's needed is for prepping styrene, using a 2" brush to soften the surface so that I can then cover it in gelled contact cement, which worked well for applying printed Kingmill paper buildings. Unfortunately, Kingmill is no more.
Otherwise, the "real" lacquer thinner and the MEK, when being used, are in small bottles with brush-in-cap applicators, and always closed when not in use.
doctorwayneAfter reading on this Forum about MEK as a glue, I found a source for it, and it works reasonably well, but does evapourate much faster than the old-style lacquer thinner.
MEK and MEK substitute evapaorate quickly. It needs to be reapplied with sufficient frequency to "soften" the joint, so that it melds together and then dries together as a solid piece.
I was disappointed with MEK substitute when I first used it. Then, I was attempting to restore an older delrin diesel loco truck sideframe that had been painted with rattle can paint. I dunked the truck in a small container of MEK substitute (just enough to cover the truck) and figured that a 10 minute dunk would soften the paint. Well, it softened everything so much that the details of the truck were gone and it looked like a blob of plastic.
So, IMO, MEK substitute "softens" the plastic and welds a crack much better than I first thought, but it may not act as quickly as the old stuff.
And the evaporation ability measn the container needs to be closed tightly so the fumes do not escape.
Edit: I think modern diesel truck sideframes are delrin and not styrene.
MEK is actually Butanone. It got named Methyl Ethel Ketone to sound impressive. That was before Ketones were found to be carcinogens. MEK is not a carcinogen. It does have many other hazardous qualities. There are multiple MEK substitutes. Read the label to verify what you have.
If MEK gets into your eyes, it can cause blindness. It is also very flammable.
The good news is that a pint of MEK lasts a long time-if you use it primarily for "welding" styrene. I use a hobby glue bottle with a fine point tip to dispense MEK onto a surface.
a suitable version is Dr. Mikes CA, it says right on the label that it is effective on Delrin .. it's about 4 times the cost of regular CA
Bowser on their website specifically recommends LazerBond.
It forms a clear acrylic bond between the two handrail pieces. It cures with the UV light that is provided, in 5 seconds or more. Bowser specifically does use it for handrail repairs (anything repaired gets sold in their retail store at a discount as a used item, per Pennsylvania state law). It works very well. I have used it too.
Before you set it with the UV light, you can wipe off any excess. It forms a pretty strong joint that is unlikely to break again.
It dries shiny clear. Avoid being sloppy and getting it on adjacent paint surfaces as it can mar them a little bit. I've successfully sanded out my mistakes with 3000 grit...