fixing a crack in a shell for F3

Classic Toy Trains Forum
1

My thoughts are to use testors glue - Separate the crack a little - lay down glue on the edge - then allow to setup. I plan on repainting the shell.

Any other thoughts on how to fix?

Also what about repairing a screwhole on the front that is cracked?

2

Be careful to apply any “solvent glue” sparingly as it will likely remove the paint if it runs down it. *

Some might recommend a good quality, fresh, thin cyanoacrylate glue (“CA” glue; “SuperGlue”).

You might consider some very good tape, perhaps reinforced with fiberglass strands, applied (on the inside, of course); or a good-quality epoxy putty to bridge the gap and/or reconstruct any missing parts. Sometime screw holes have enlarged. One technique is to fill the entire area and then carefully drill a new hole.

There was a pretty good article about repairing a tender shell posted on this forum about a year ago, as I recall. It had step-by-step instructions and good photographs. (Here’s a link to one thread on the subject. There are other posts. Try an advanced search under the author’s name.

http://cs.trains.com/forums/1/1235316/ShowPost.aspx#1235316

  • Edit, based on a subsequent post. In this case the owner plans to repaint the shell. In the more general case, however, ruining the paint would be a catastrophe. Hence the caution.
3

Or, you could apply plastic weld to the inside and let it be. As the instructions will tell you, there is no need to spread the sides since the product spreads through osmosis. Since you plan on re-painting there’s no wories about ruining the paint.

Mike

4

I’ve stuck with the liquid Testors approach because the bond this glue creates is very strong if you do it right. I have used it extensively.

BF has it right. Use this stuff sparingly. If it gets on the paint, the paint will be history and worse. If you want to melt your exterior surfaces and leave your fingerprint permanently imbedded on the exterior of your F3 shell, this is the glue for you. It runs like water. At least if someone steals your trains and the police recover them, you can prove forensically through the fingerprints that they are indeed yours. [:D]

The liquid Super glues can be just as effective as the Testors. I worked with Testors and epoxies long before there were the so called Super glues. For me, I have just found the Testors’ bond great and it’s applicator effective in limiting the amount of glue applied.

I first thoroughly clean the exterior of the shell around the crack. Then I apply the blue 3M painters’ masking tape on the shell exterior over the crack, if possible, taking care that it is adhering well over the crack. This will prevent any seepage of the liquid Testors (or Super glue) applied on the inside of the shell to make its way all the way through the crack to the outside of the shell and onto the exterior paint. The tape should stop any unwanted seepage that gets that far. And this particular brand/type of tape is easily removed without damaging your paint, numbers, or decals.

The capillary action of the Testors is adequate enough to find it’s way into the crack, not just on it. So spreading the crack to get glue into the crack is usually not necessary. The glue usually find

5

Tenex 7 applied on the inside of the shell by means of a small paint brush (000) or a draftsman’s ruling pen. Do not try to separate the crack, the capilary action will wick the stuff in. Use very sparingly.

Liquid Testors tends to be more aggressive and sometimes softens the area around the glue joint.

Epoxy on the inside will also work in terms of stopping the crack from spreading but it will not actually seal the crack.

Supper glue doesn’t actually weld the seam and the crack could break open again under stress.

6

**Chuck…**You’re right on the Testors! Early on I found this to be exactly the case. I quickly realized that I was fixing one problem (crack) while creating another (softened plastic) with my overkill. More was not better with this product.

Less product, patience, and a better thought out plan of attack was better, if not optimal. I always thought that shell cracks, like around screw holes, were better repaired permanently by figuring out the initial stressors and eliminating them while doing the repair.

Some of the stressors were simply a matter of the screw hole being slightly too snug, fixed by a minute radiusing. Others by recognizing the amount of stress could be mitigated by something as simple as the addition of washer to spread the stress load. Derailments, rear end collisions, or careless handling of the engines, another topic for another day.

I enjoy reading others opinions on products I have not used and techniques I have not tried.

Jack