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plastisc glue??

Started by union pacific 844, February 06, 2013, 03:35:25 PM

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richg

Quote from: union pacific 844 on February 06, 2013, 03:35:25 PM
http://www.ebay.com/itm/330868691976?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649 will this hurt engine paint?


Any adhesive that can bond plastic will affect paint. Plastic is softened by the adhesive and actually cause the plastic  to flow a little.
Common sense says to glue first and paint second.

Rich

ebtnut

The Testor's cement isn't quite as attack-prone as some others such as Tenax.  However, I would err on the side of caution.  It can damage some factory paints.  If you can find a hidden spot on your model that is painted, put a small drop of the cement on there and let it set for an hour or two then look closely.  If there is ANY orange peel, crinkling, or crazing, the don't use it in a visible location.  

richg

This should be the MSDS for the product from Testors.

http://tinyurl.com/a4496aw

I have worked with chemicals for years and the first thing I do is a search for the MSDS on a product.

Rich

electrical whiz kid

EBTnut;
I hav e seen that written in directions as standard fare on a lot of adhesives.   It should be pretty obvious that anything as volatile as Tenax, Testors, etc, should be read up on thoroughly.  There is a product called "Barge Cement" that I have seen advertised pretty much exclusively in Central Valley's catgalogue.  What has been your experieince with this compound?  I am proceeding to laying track per CVT system, and this product is supposed to be used.
Rich C.

Desertdweller

Testors makes both a thin liquid plastic cement, and a thick type that comes in a tube.
Both will attack paint.  It is important to remove the paint on both parts of you want to get a good bond.

The tube-type cement contains a clear filler.  They also make a tube type cement for wood, and a tube-type cement that is supposed to be non-toxic.  That stuff comes in a blue tube and is made from a citrus base.  It does not give a vary good bond on plastic, but will attack paint.

"Barge Cement" sounds like it would be a pretty heavy-duty industrial stuff.

Les

Doneldon

844-

The thin, watery, solvent cements work by melting the surfaces of the plastic pieces to be joined, essentially welding them together quickly. Thicker solvent cements also melt the surfaces though not as effectively. They have additives to give the glue some body and, in most cases, better control over where the glue goes and a longer open or working time. Or at least that's the intention. In practice, the thicker materials have a tendency to get on places where they aren't necessarily desired and their retarded curing/drying time means that a renegade drop somewhere on a work surface remains a threat to our models for a comparatively long time. (To be fair, it must be said that a spilled bottle of watery solvent has the potential to ruin both the model we are working on and the table and floor where we are working.) Both types of solvent glue result in a rigid joint, the liquid being a bit stronger than the thick in this regard. However, none of that means they both don't deserve a place in our glue box.

My point is that both of these products, and several other adhesives, have a role in our model building, customizing and repairing. The trick is in knowing when to use which.

I find the liquid glues best (by far) when I want to be able to hold two pieces together for a moment and have the joint suck in the adhesive by capillary action. An example might be a corner where two walls of a building meet. I can hold these in position, add a drop or two of liquid glue and have a good joint in seconds. Or, perhaps I want to melt the post of a detail item into its hole on a structure or locomotive. I put the detail in its hole, add a tiny drop to the reverse side and have a strong, unmarred surface with my detail securely attached. In both cases, the joint is strong right away so I can go on to my next task. Thicker glue is better when I need a few seconds to get something in exact position and perhaps don't have guide pins to help, or when I have two large areas to join like layers of the walls of a structure. Please note that both of these glues are designed to hold two pieces of the same kind of plastic together. Each will work a little on unlike materials, the full-bodied one better than the thin- in this application, but generally not the first choice when joining a piece of plastic to metal or wood.

There is a version of the weld-it glue which will join plastic without the potential to fog clear plastic parts like windows. This doesn't make an especially strong joint but it is great when used for what it is intended. So-called household glues are better when we want to join unlike materials. These come in both rigid and flexible forms. There are too many rigid household glues to mention but the choices for flexible bonds are more limited. In model glue, Walther's "goo" is probably the best known and most widely used. It's been around for decades and is a good product. I prefer Barge cement. (Les: This is the name of the company which makes it. It has nothing to do with unpowered floating vessels which are pushed around by tug boats. It's interesting, and probably gratifying to the manufacturer, that you inferred from the name that it is strong stuff.) This is an excellent product, IMHO, and I find it particularly useful when I need a join which needs to flex some. Mostly I use it on leather. (I also make knives and their sheathes.)

Then there are the numerous forms of wood glue. I don't especially care for the solvent-based wood glues which are sold for model work. To me, they have all of the messiness potential of thick plastic solvent glues without the reliability and quick setting of solvent-based plastic glues. Plus, their joints aren't very strong and they can really fog clear plastics. I prefer Elmer's Carpenter's glue or, occasionally, white glue. By "occasionally" I mean "when I can't find the carpenter's glue." I also like Gorilla Glue for wood joints but its tendency to foam and expand, plus its long curing time, make it relatively useless for model work. It's great, however, for benchwork and furniture building or repairs, yet another of my hobbies over the years.

Many adhesive caulks and construction adhesives have their place in model working, at least in regards to benchwork, scenery or perhaps laying roadbed and track. They aren't especially useful for actual model work.

The last kind of glue which comes to mind is the family of super glues or ACC glues. These seem to have a limited shelf life but it's great that they come in varying viscosities and open times. I cannot claim to have had much success with them, so I don't use them. However, I'm aware that some modelers swear by them.

All-in-all, adhesives are a science in their own right. Most, if not all, have a defined use; the trick for us is knowing when to use a particular
type. Use the correct adhesive and you are likely to get a strong, durable joint. Use the wrong one and you will get an unsatisfactory joint
at best, and perhaps a huge mess.

                                                           -- D

union pacific 844

i need to re-glue the cab roof back on my 844 4-8-4  

Doneldon

844-

You have to stop picking up your locomotives by grabbing their cabs!

This sounds like a job for mighty glue, plastic variety. Use the thin stuff if you can easily get to the underside with the applicator and won't drip on an exposed area. Otherwise, use the thick. I'd probably put a little on the cab walls and then fit on the roof. I think that would be less likely to mar any visible surface. Be sure to keep the glue "biases" to the inside of the cab rather than the outside.

Good luck. Let us know how it turns out.

                                                                    -- D

Desertdweller

Doneldon,

Thanks for straightening me out on the Barge cement.

I had visions of a product that came in gray 5-gallon buckets, for application with a stiff push broom.

I like to use the gel-type superglue for plastic models.  I also like the Locktite brand flexible cement for vynal and fabric.  It is useful for things like gluing lead weights inside car bodies.  It would probably work well for leather work, too.

Elmer's Glue is a great product.  Elmer's Wood Glue is great for things like attaching foam insulation board to plywood, as well as wood-to-wood joints.  Unlike a lot of glues, the Elmer's Glue products will not attack foam plastic insulation.  The wood glue is stronger than the Glue-All.  The Glue-All has the advantage of drying clear.

I had an unfortunate experience gluing sheets of styrene together with the thin liquid solvent.  For some reason, the solvent wouldn't dry when in between the sheets, and left a depressed pattern on the outside of the sheets mirroring the pattern of the applied solvent.  Maybe it would have helped if I had let the solvent mostly dry before putting the pieces together.

When Glue-All first came out, I tried to use it to assemble plastic models.  They soon fell apart.  The materials have to be porous for it to work.  And it won't stand up to immersion in water (You can glue the broken handle on a ceramic teacup, and it will hold until you wash it).

Les

Jhanecker2

Testors Liquid Cement & their Tube glue have been  used in the Chicagoland  Area since I started building styrene models in the 1950's .  A word of caution,  when using  CA cement always have acetone and / or nailpolish remover  around  to separate  accidentally glued body parts .  Cyano- Acrylate  cements are great for dissimilar materials that need immediate setting ,  but marginal for styrene . in my personal experience . J2

union pacific 844

where the is going under the cab roof where you can only see if your ho scale and inside of the cab

electrical whiz kid

Doneldon;
My reference to Barge Cement was from CVT.  I understand that it's use is to provide a conditioned surface for rail to adhere to the tie system that CVT has.  I was looking for feedback for that application.  I am really looking forward to using that track system.  As soon as the guy comes to repair the sheetrock ceiling (roof took a direct hit from an extremely large oak branch-it could have been arrested for breaking and entering, I suppose.)
Rich

Doneldon

Rich-

I'm sorry to hear about your roof. Between the calamity itself and the hassles with the
insurance company a th8ing like that can be an awful experience. I hope tings get
straightened out for you soon.

Barge cement should be a good adhesive for holding rails to ties. It is tenacious and has
just enough give that using the tracks shouldn't stress it and cause a failure.

                                                                                                      -- Doneldon

ebtnut

To minimize stress problems using the Central Valley tie strips, I would consider pre-bending the rail for curves.  Fast Tracks makes a rail bender (though currently out of stock).  You do still have to be careful about soldering feeder wires and rail joiners with plastic tie material.