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Any ideas on how to fix diecast model?


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Back in June I got two Ertl Precision diecast tractors at an auction. One is a Ford 9N. The 9N has a broken front axle. I know it's not a car, but it still has four wheels and an engine. :D I was wondering if anyone knows of anyway to fix it? I've tried epoxy and JB Weld. I have not had any luck with either. Does anyone have any out-of-the-box suggestions? When the axle is in place, you can't really see the break, so any suggestions would be welcome. Here's a couple photos. One shows the break and the other how it's suppose to look.

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Edited by JayC
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I'm assuming that the break is at the pivot point on the front axle. You may have to reinforce the axle with a bit of brass or plastic strip epoxyed onto both halves of the axle. There will be quite a bit of stress on the joint because the weight of the tractor's engine is all on that pivot point. You may have to sacrifice the pivot and glue the axle solidly to the tractor.

Carl

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Thanks for the replies. Sorry for not including more photos. I've got more. The camera didn't wanna focus right on the axle piece so I had to throw a little cloth to help it focus where I wanted it. I hope you can make out the break on the pictures. The frontal shot shows how the axle sags when in place.

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The area on both sides of the break is so small I'm not sure how I could get something like an aluminum rod in there. It would sure help if I could get the thing taken apart, but I have no idea how to do it.

I have a feeling your fix didn't work because you were trying to glue painted surfaces together.

There was a little overflow of the JB Weld onto paint, but the surface on each side of the break was clear of paint.

I'm assuming that the break is at the pivot point on the front axle. You may have to reinforce the axle with a bit of brass or plastic strip epoxyed onto both halves of the axle. There will be quite a bit of stress on the joint because the weight of the tractor's engine is all on that pivot point. You may have to sacrifice the pivot and glue the axle solidly to the tractor.

Carl

You hit the nail on the head. The break is such a small area, but has to hold a lot of weight. When I got this thing, I was shocked at how much it weighed. I never knew a Precision weighed so much, since these two were the first. The other is a 2N, so they are nearly identical. I think the main issue is that such a small area is holding so much weight. I don't know how well the photos actually show it, but the break isn't a clean, half & half break, either. I think that makes it even worse. I have a Dremel. Would it be worthwhile to try and grind a larger surface area out of each side?

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I'm thinking a small brass rod drilled into both sides and JB Welded in place.

Foxer has the hot setup if the repair is going to be visible. But I'd recommend 1/16 steel welding rod, if there's enough meat on the axle to drill it for that diameter. Go at least a quarter inch deep on both sides of the break. I'd also recommend a slower-cure epoxy than JB. The longer an epoxy takes to cure, the greater its final strength will be, in general. There's very little bonding area here, so you need all the bond strength you can get. I'd also recommend a structural thickening agent like milled fiberglass or cotton fibers. They add tremendously to the strength of a cured joint. And make sure the rod is well-scuffed and cleaned and that the epoxy gets dowm in the holes.

I've used the inserted-pin technique to sucessfully repair a lot of things, including a little girl's favorite toy horse that had a broken leg. She's all grown up now and the horse is fine.

Jantrix has a better solotion if the repair won't show. It looks like you have an I-beam axle, so some flat, metal strip-stock epoxied inside rhe recesses of the I-beam, after removing the paint, will reinforce it very well, better than the inserted-pin method. Get a good fit on your strips and JB should work fine, as you'll have vastly more glue contact-area.

Edited by Ace-Garageguy
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The repair won't really be visibile. The break is right behind the grill near the edge of the chassis. I'm not against bracing it up like Jantrix says. The only problem is everything is so tight I don't think I could get anything in there. I'm kind of liking the pin idea as I think I could do something with that. I was wondering, I have some black 20 ga. wire layin around, would that be ok to use to pin up the axle? It looks like it would be the right size.

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My trusty wire diameter finder lists 20ga. as being about .030". It kinda depends on what kind of wire it is as to how stiff it is in bending. Steel piano wire will be stiffer than brass, etc. Also think about how the repaired joint will be loaded. Epoxy in the drilled holes will put the glued-in wire in tension when weight is put on it, (assuming the ends of the axle are firmly stabilized square to each other) and the tensioned wire will hold the ends of the broken axle together and, theoretically prevent them from spreading apart enough to 'rock' relative to each other, allowing it to sag. The inserted wire won't really be in bending load unless the broken ends can spread apart slightly. So.....if all of your epoxy work is fully cured, and it's all applied to bare-metal (epoxy will stick to paint, but the ultimate strength will only be the strength of the bond of the paint to the metal), I THINK .030" wire would do it. I'd still tend to handle it carefully post-repair.

1/16 steel wire (welding rod) or a broken drill bit would be better if you have room.

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The wire I have is rather stiff. The reason I mentioned it is because it looks like it would be the right size to pin up the axle. I'm afraid if I were to start drilling the axle with a 1/16 drill bit I might break it. It would be kind of a tight fit. The break isn't a clean, straight break either. Would it be advisable to take a Dremel, and grind the edges down so they are flat?

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That's what I was thinking, too. I don't want it to look out of sorts with a shaved axle piece. The pieces do go together ok. My big fear is, if I can find a drill bit small enough, the axle breaking and the whole thing getting ruined. Drilling a hole to pin it up is really the only way. It's far too tight to get anything in there. Is diecast metal easy to drill? I've never done it before.

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I have done a few of these. The pinning idea should work fine. I drill the hole in each side as close to the center as I can, it does not have to be perfect. Many times I just cut a short piece from a paper clip and drill the hole one size larger. If the holes are off some and the parts don''t line up drill one side a little larger. Do this alternating holes until it does line up. I use 5 minute epoxy, coat the pin then push it into one side while turning it to work out air pockets. Coat the pin and work it into the other piece. Hold in place until cured. You are going to have some epoxy squeeze out of the joint. If joint is not visible I would just spread it out along the axle.

If you can't get a long bit in there you can use a pin vise, it should drill rather easy. Start with a smaller hole first.

I have had the hood off of those but don't remember how they come off.

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I finally got the thing apart today. I got the axle removed so it'll be easier to work on now. However, when trying to drill it the bit just slides around. I can't get it to grab. I got to thinking, since I have the axle out now would it be possible to solder it? I have a couple soldering kits laying around. If not, since the axle is out now maybe JB Weld will work better now that I can see what I'm doing.

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Die-cast is typically a zinc-based potmetal, meaning whatever low-melting-point metal was lying around got tossed in the melting-pot. There are a FEW specialty solders that will actually stick to the stuff, but the odds are not in your favor. It's possibly worth a try, but don't use a torch on it or it just might go away.

As far as drilling holes in irregularly shaped parts goes, I usually start the hole by making a depression with a diamond tip in the Dremel. If you can get an accurate center, you're halfway home. If you don't have a Dremel, you may be able to file a vee-groove across the break and get your drill started that way. Putting the axle ends in a vise and center-punching with a pointed punch and a small hammer is another effective way to start a drill-hole.

For JB Weld, with such a small bonding area relative to the weight the joint will have to support, I'd bet against it if it's a simple butt-jiont (just gluing the ends back together). You'd be definitely better off going with Jantrix's solution of gluing reinforcements to the outsides of the axle.

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