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How to fix diecast toys

I’ve told you about the best way to fix plastic toys, but it dawned on me the other day I’ve never mentioned how to fix diecast toys. Diecast toys don’t break as often as plastic, but it can happen. The good news is that you can fix them too.

In my example I will be fixing a Lionel 671 train from 1946, but the same technique works with anything made of diecast metal of any age.

The best glue for fixing diecast toys

This is a broken piece from the cowcatcher of a diecast Lionel 671 locomotive.

This is a broken piece from the cowcatcher of a diecast Lionel 671 locomotive.

The best glue for diecast metal and fixing diecast toys, bar none, is JB Weld. If you’re not familiar with it, it’s a super-strong epoxy that sets up and cures harder than steel. It’s more brittle than steel, but it still makes an exceptionally durable bond.

The downside to JB Weld is that while it sets up in a matter of minutes, it takes 16-24 hours to fully cure. So you really need to leave it undisturbed overnight while it does its thing. But once the epoxy does fully cure, the repair is rather strong. Arguably the strength is comparable to the diecast metal itself.

The faster alternative for fixing diecast metal

I've applied JB-Weld to the break, as well as a bit to the area behind it to build it up for extra strength.

I’ve applied JB-Weld to the break, as well as a bit to the area behind it to build it up for extra strength.

If you need a faster bond, you can use Kwik Weld. Made by the same company, it sets up in a few minutes and fully cures in a few hours, at the expense of not being quite as strong. Another option is to tack the repair into place with a bit of Kwik Weld, then finish the job with slower JB Weld. But for most purposes, the Kwik Weld variety has plenty of strength and is worth the tradeoff.

Prep work for gluing diecast

Prep work always pays off when gluing up a repair. Clean the surfaces that you will need to bond with some alcohol or mineral spirits to remove any dirt and oil. This gives you the strongest bond possible. Once the surfaces dry completely, you’re ready to glue.

How to glue diecast

Rather than remove the excess, I smoothed it out a bit. After it's dried, it will need to be sanded and painted.

Rather than remove the excess, I smoothed it out a bit. After it’s dried, it will need to be sanded and painted.

Both of the varieties work the same way. Mix up an equal amount of the two parts on a piece of scrap plastic, such as a food container you’re going to throw away anyway. Stir it until the color is a consistent medium gray, then slather it onto the edge where the broken-off piece will go, then press the broken-off piece into place. Clamp the pieces together tightly after applying it, if possible.

Once you get the glue into place, you can smooth out the excess with a wooden coffee stirrer or popsicle stick. JB-Weld does an excellent job of gap-filling, so if the pieces don’t fit super tightly, it will still hold. If you can, build up some excess on the back of the repair to give it extra strength. Let it cure for the appropriate time.

Once the epoxy cures to full strength, then you can sand the repaired surface  smooth and touch up the paint as needed. Patience is the key. It takes some time, but it’s worth the wait.

I've reinforced the repair from the back with a generous amount of extra JB-Weld where it won't be visible.

I’ve reinforced the repair from the back with a generous amount of extra JB-Weld where it won’t be visible.

Depending on which variety you used, the repaired piece isn’t necessarily quite as strong as the original, but it will be close. JB Weld is more durable than Kwik Weld.

It works for me

I’ve used JB Weld and Kwik Weld to rescue more than one Lionel train that took a dive off a table. It works well. And it will work on other diecast toys just as well, whether you’re performing a repair or restoration, or performing extensive modifications to pieces you had to saw and now need to glue back together.

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