Fixing old molds

I have a bunch of my buddies old mold and they need some serious work. Most of the pins are corroded shut and I can not hammer them out.

Does anyone have any idea short of drilling them out to get the broken pin pieces out?

If you have acess to an air compresser a cheap diegrinder and thin wheel will cut right through that pin from the side and you can remove it a lot easier.Wear your safety glasses.

That would work but the pin is corroded and stuck in both the insde and outside hinges. I tried drilling the pin and I got 1/4 inch in about 5 minutes so that aint gonna work.

I have a Dremel which will work for the stuff that isn't completely stuck but I don't think any of them will be that easy.

F4A, having work in machine and welding shops most of my life I've had many similar job to do. I'm assuming the mold are aluminum and the pins are steel so you will have to proceed carefully.

If the molds are aluminum, you don't want to bang on them too much because you could bend the hinge out of alignment. You could try applying some heat carefully to the hinge and then let cool. The heat will help break away the corrosion that is holding it together. Sometimes a repeated cycle of heat and cool and soaking with penetrating oil can work wonders.

If that doesnt' work I would cut the molds apart by cutting the pins between the hinges using either a fine cut off wheel or a hacksaw. Either way, you will end up with slack and will have to use some shims to tighten them up when you are ready to re-assemble. By taking them apart you can more easily work on them.

After they are apart it will be easier for you to try to drive the pins out, but to do so you will need to have the right support under them. You will need something that won't give or bonce, perhaps something with a hole in it to allow the pin you're knocking out go in. You might try heating them a little and then try to drive them out. Just be sure you have no part of the pin sticking above the hinge to flare out when you start hammering and be sure you use a perfectly flat punch of as near the size of the pin as possible.

If you get nowhere that way then you need to try drilling again. In your first attempt was it the harden pin or just a dull bit that stopped your progress. You might want to try another bit and be sure you keep it cooled and lubricated. Definitely a job for a drill press and slow speed. You didn't mentioned if they were solid pins or rolled pins. Roll pins would make the drilling easier but even if you do drill a little off center and remove some of the mold all is not loss you can solve this later.

If and when you do get them apart and the pins all out you will need to realign the two halves which might be accomplished by putting the correct size jigs into the cavities. Then with the halves aligned and clamped together, drill the hinges with either the correct size drill bit or one slightly larger. Make sure you get new pin material before drilling so that you drill the hole the exact size needed. Brass pins might help stop the corrosion part and next time the drilling will be easier.

I hope this gives you some ideas and most of all get the job done. By the way, how many do you have to repair?

Good luck,
"gene"


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Thank you a ton, gives me a lot to try. Heating is easy and the rest will just have to be patience and time but I am hoping it doesn't come to that.

i had a few like that and i just put them on top of my pot and got um really hot and jerked them open and kept working them back and forth and now they are good as new

I wish these were that easy but they all either opened fine or the pins broke when I opened them. Nothing is ever the easy way for me this time of year.

So far no luck. The pins are hard and I don't have a bit that will drill them. Tried heating them oever and over again, and over again and it didn't help me get them out. Gonna try a special oil I was told about that is supposed to penetrate and remove corrosion but not holding my breath.

Thanks for the ideas everyone.

You are going to have to get a good hardened carbide bit,like the kind used to drill spot welds out of sheetmetal parts in the autobody business and a very slow drill.