Attaching small parts with glue

[Anonymous]

I have read that some use a bru***o apply glue to small parts. Do you use a certain type of glue that is very thin? Doesn't the brush get caked with glue after a few applications, or do you use some type of solvent or cleaner to keep the brush clean? I just bought a bunch of P2K freight car kits (not time-savers) and I am not sure of the best glue or method of attaching all the small parts. I normally use Testors liquid model cement for small parts and the thick stuff in the tube for large or unseen areas, but I don't know how to apply such a small amount for things like grabs. Any advice?
Tim

[Anonymous]

Best trick I've found is to use a small piece of wire - you'll be able to scrape the dried glue off afterwards and it'll allow you to apply a small amount of glue accurately.

[orsonroy]

On plastic to plastic bonds, always go with LIQUID plastic cement, not the junky "airplane glue" that comes in a tube. Testors, Tenax and Ambroid make the three most commonly available LPC, and each are a little different. Tenax evaporates the fastest, Testors is the most aggressive, and Ambroid is somewhere in between. I use Ambroid for most bonds, and Testors for interior stuf like bracing.

Ambroid Proweld works great on P2K freight cars, as it will melt the paint that's on the parts, meaing that you don't have to scrape and ream before you build the kit. Grab the small part with a pair of tweezers (I prefer the kind that OPEN when you squeeze them), and get a small (00 or 000) natural fiber paintbrush. Apply a small dab of cement to where you want the part to go, and then add the part. In about 1-2 seconds, the bond will be complete. If the part looks a little loose, add a little more cement. Using a natural fiber brush means that the cement won't attack the bristles, keeping them clump-free.

[retsignalmtr]

i have had good success applying small amounts of glue using a tooth pick. including ca types of glues.

[mcouvillion]

The "liquid" cements are really solvents that effectively "melt" the plastic where they are applied. You can use a small paintbru***o apply the solvent to the edge of a part then position the part on the mating piece. For items that fit in holes, fit the part then apply a small amount of the solvent from the inside of the model. Capillary action will usually wick enough solvent into the area of the joint to make the bond. The solvents will evaporate from the bristles of the paint brush, which you can then use again and again.

For thicker glues (airplane glue), try using a round toothpick. Place a small drop of glue on a piece of wax paper, then work with that after closing the tube. Many glues get stringy as you try to use them. (Walthers Goo is the worst. I still have trouble applying that stuff.) Always seal the tube quickly so that the solvent in the glue does not evaporate and leave you with a solid tube. Never apply glue directly from the tube (unless you need a lot over a large area).

Practice on older stuff before doing your expensive kits.

Mark C.

[Anonymous]

Tenax in particular is such a strong solvent that it actually cleans the brush as long as you wipe it on a paper towel or tissue.

[Anonymous]

I have good results using a straight pin stuck in a dowel "handle". I then cut the head of the pin off and sharpen the end. Glue can be applied exactly where you want it.

[SPFan]

I insert the part dry then use a pair of smooth jaw pointed forcips (tweezers) to transfer the solvent. Hold the tweezers closed and dip into the solvent. A small drop will form the space between the jaws. Put the point against the model and release the solvent into the joint. Very small amounts of glue can be transferred by this method depending how far you dip the point into the solvent. Folks who still remember a draftsman pen will recognize the principles here.

Pete

[PennsyHoosier]

I have all kinds of glues around for the RR. However, I had a computer disaster recently. My DVD drive broke. I used Ambroid to repair a broken DVD drive. It worked VERY well. That convinced me of the strength of that approach. Use the right glue for the right situation.

[Anonymous]

I have a bottle of Tester's liquid in which I have cut off most of the brush fibers. There are maybe 10-15 fibers left. This allows picking up a small amount of liquid and controls very well were it will be placed. When I use CA and want small amounts, I place one drop of CA in a very small container or on a small piece of flat plastic and I use a common pin to pick-up and place a drop of CA.

I have found both methods to work extremely well!

[Anonymous]

Thanks for the help. I am going to try the brush method as I think it will give me the most control for what I am doing.
1 more question about gluing, though. I just started assembling some American Limited sanding towers. This is the first time I have had to try to glue metal to plastic. I have tried CA and it doesn't seem to hold. Do I need to do something else when attaching dissimilar materials? Are there different types of CA for different purposes? I am using the inexpensive 3 tubes for $.99 stuff. Is there a difference?

[orsonroy]

Realistically, the only difference between superglues is in their fillers. There are a few industrial and medical glues that are different, but the average modeler will rarely see those on his workbench.

I'm a bit surprised that you're running into issues gluing plastic to white metal, but I've seen the problem before. Generally, dirty castings are the culprit. Clean both the plastic and the metal with a grease-removing detergent, and poli***he white metal (a cotton pad in a Dremel tool works great). Make sure the parts fit together properly, and add a THIN layer of superglue.

Keep in mind that white metal (along with every other metal) will oxidize, and that the oxidation will eventually degrade the superglue bond (as well as epoxy bonds). Depending on the metal and it's environment, the process can take several years, or only one or two. Don;t be surprised if you have to reassemble the kit in the future!

And remember, superglues have REALLY bad shear strength, so it you're assembling a part that will be subjected to lateral thrust or torque, you'll have to try something else (like epoxy and pins).