Need help with glue

Model Railroader General Discussion (Model Railroader)
1

I am/was about to start building the Woodland Scenics “Sicken Tire Company”. I cut off a piece of scrap plastic from the kit and tried to bond it to another scrap piece. I first tried lacquer thinner with no luck, I then tried Super Glue “The Original”, same results, neither one did a thing. Do I need to get my arc welder out or what.

Any suggestions would be greatly appreciated.

Thanks for the help

Ken

2

Ken,

Plastruct Plastic Weld, Tenex 7 Ambroid Pro Weld,the original formula,works best,new formula,is ok ,But I prefer the old,Thank God,I have a half of case left,Testers liquid is ok, a superb CA,Is Zap-A-GAP,Medium CA+,BONDS,almost anything,with strong joints, That is only to name a few…I’m surprised the Lacquer thinner didn’t work…

Cheers,

Frank

3

Thanks Frank

I cut off a coulpe pieces of spru (I think thats what you call it) to try the glue and there was no melting of the plastic at all. Would trying the spru have anything to do with it? I would hate to experiment with the building.

Fortunatily tomorrow I have to go to Tyler Texas where there is a hobby store, its 110 miles from here so I don’t get there very often. Its nice living out in the sticks but it has its down side.

Tthanks for the reply, I wrote all your suggestions down.

Ken

4

Plastic kits are styrene plastic. The “plastic welder” cements, clear thin liquids, work by dissolving the styrene into soft sticky goo. Slight pressure on the joint causes the goo from both pieces to meld together. Then the solvent cement evaporates and the goo turns back into solid plastic. The commercial ones, Tenax, Amboid, Testors, etc come in one ounce bottles with a brush in the cap for $4.00. Really active solvents that cost less, come in quart cans, are lacquer thinner and MEK. I use MEK myself. If the plastic won’t dissolve in MEK it ain’t styrene, or your solvent ain’t MEK.

I never noticed any difference between the various brands of solvent cements. They all work fine for me. MEK is somewhat more active than lacquer thinner, but many folk report good results using lacquer thinner.

Your joint has to be fairly close fitting. The solvents / solvent cements have no gap filling qualities. Unless the styrene surfaces press flatly together the joint won’t hold. The joints in injection molded kits fit plenty closely. Did you test joint fit well?

A solvent cement joint in styrene plastic will be as strong as the native styrene. I don’t use superglue on styrene, I think the solvent cement works better.

5

Ken,

One thing,I forgot to mention,is to wash the parts,in something like dish soap,with warm water,to remove any mold release agent left on the parts,that also helps a lot,when gluing them,

Cheers,

Frank

6

David brought up a good point about parts fitting. Since the sprues are round, I filed them flat and tried it again. The surer glue did hold, but the thinner did nothing and I put enough on that it was running down my arm.

Tomorrow I will take the list and a sample of plastic and hit the model shop.

Thanks everyone for the imputs.

Ken

7

I use the Testors glue in the small bottle with the brush applicator inside. It is NOT the most cost effective, nor is it the strongest. However, I do most of my modeling indoors, and with New England weather, open windows aren’t always very comfortable, so the more aggressive glues tend to smell up the place and give me headaches.

I’ve often found that the glue gets weak near the bottom of the bottle, so having a small bottle lets me use almost all of it before it needs replacement. I’m not sure if this is an “exposure to outside air” thing or contamination from the brush in the cap, but I’m glad there’s so little left when I have to toss the bottle.

8

Thanks everyone for your info. You folks are a big help.

9

You should whenever possible have that parts already in position and then add the solvent, sapilary action will draw the solvent into the joint. If you try to add the solvent first and then put the parts together, shances are that the solvent will evaporate before you get any melting action.

10

Thanks, I didn’t realize it evaporated that fast.

Can you apply it with a wood toothpick?

Ken

11

I don’t think that it will carry enough of the glue to allow it to flow into the joint. A small paint brush or a micro brush will work better.

Joe

12

thanks, this is my first try at plastic, every thing else has been wood. I am begining to think wood is easier.

Ken

13

Never had any trouble using lacquer thinner on any plastic kit. I did a test & used Testers, Plastistruct, Tenax & thinner. The thinner was the only solvent that the part broke before the joint. The test was done on Evergreen styrene. jerry

14

I think “which is easier” may depend on what you are used to. The thing I have to remember with wood is to be sure everything I want stained, is done before I glue. Glue doesn’t take stain. I haven’t done a painted wood project yet, but do know that I have to watch out for warping, usually by priming both sides of the pieces.

Have fun,

Richard

15

I’d recommend MicroWeld. It’s non-toxic but don’t let that fool you. It will melt styrene together like no other and doesn’t evaporate as quickly MEK giving a little more working time then a split second. [8D]