I've lived in the south too long

I forgot how to deal with rust.

We'll, not body rust. Very familiar with that. But more of the "this E36 M3 is welded together with rust" sense.

My current project is to restore a pair of 50's era craftsman table saws. On the one, the ferrous metal miter gauge is rusted into the cast table top. Unknown if the top is steel or cast iron. Same with the miter gauge. Im assuming top is cast iron and gauge is steel.

So, how the hell do I get these apart without mangling anything? Im hoping for completely damage free.

Ive been soaking it with pb blaster and tapping with a deadblow hammer for two months, and still got nothing. Its pretty precise fitment wise, so im not sure how far down the penetrant is actually getting.

The table top is two foot by three, so unless you have a genius idea of how to do electrolisis, I don't think its feasable.

This might should have gone in offttopic, but I figured that this issue is more automotive than anything else.

Anyway, this miter gauge is the only thing that is slowing me down from getting to the next step in my garage rennovation.

You might use the Evapo-Rust that David used on his bike parts. Build a clay dam around the offending part and fill it up. I price it the other day and it's fairly cheap.

Is it too big to make an electrolysis tank to put the whole thing in?

A kiddie pool and a truck load of vinegar. Or turn the kiddie pool into an electrolysis tank?

If that's to much space and expense then vinegar soaked rags may work, but I don't think it'll be as good as immersion.

Maybe try an industrial coatings place and see if they have acid dip tanks that they could run it thru for you.

I'm well impressed with the power of vinegar, I've recently used it to derust an early 1900s straight razor and a bunch of parts off a 1920s/30s alexanderwerks westfalia meat slicer.

I've heard a 50/50 mix of ATF and Kroil oil works wonders.

http://www.kaylinecompany.com/catalogs/K327.pdf

This stuff is wild. It's almost a game to me finding the things that this will unstick.

I'm assuming that going outside, standing upwind, and pouring a little hydrochloric acid on there isn't an option. That WILL nuke the rust. I've done that with a few things but always small parts, the biggest being the inside of a fuel rail (needed some sacrificial injectors to plug the holes) and I also dunked a V-twin crankshaft into a bucket of the stuff to melt off some bearing material after a main siezed.

That worked like a CHARM, I might add. Da Boss thought we were going to have to get the crank turned, I said nah, it's aluminum bearings, let's melt it off in Muriatic and see if the crank is scored under all that metal. Crank was fine, a few swipes with emery cloth to make sure there weren't any hidden gouges and some cleaning and it was ready to go back into service.

Hydrochloric will technically also eat the base steel/iron but that will take days as opposed to the seconds/minutes needed to turn the rust into brown foam.

I think your on the right track, but I'd add heat, and toss the dead blow for a bfh.

Knurled has the right idea, a little muriatic acid should do it, wear eye protection, have big jug of baking soda/water mix ready.

I think that the chemical based ideas are better than mine, but here is what I'd try if they don't work.

Drill holes through the bottom of the table directly under where the miter is stuck, about 1/4 inch or slightly larger. Then oil it from underneath. After the oil has soaked for a few days try to knock it out with a punch through the holes that were drilled. Assuming that the operation is successful, you can chamfer the holes with a countersink drill bit so they don't become a snagging point.

Heat , when cool use 50% acetone and 50% ATF mixture. Use a dam if necessary. PB blaster doesn't penetrate. Areo Kroil is the next best thing to ATF/Acetone.

pjbgravely wrote: when cool use 50% acetone and 50% ATF mixture.

That's called Weasel Piss.

Define heat: propane or oxy-acetaline?

Dusterbd13 wrote: Define heat: propane or oxy-acetaline?

Shoot for the middle with MAP.

Don't own any map. Learn me please.

Dusterbd13 wrote: Don't own any map. Learn me please.

This is my next-favorite shop tool, right behind the 3lb shorty drilling hammer.

Handheld instant-on MAPP torch

Can I use my propane torch nozzle on the map gas cylinder? They appear identical.

Yes you can.

Dusterbd13 wrote: Define heat: propane or oxy-acetaline?

Mapp gas is my choice of heat, O2/ acetylene would probably damage it. 1 or 2 propane torches should work too.

HappyAndy wrote: I think that the chemical based ideas are better than mine, but here is what I'd try if they don't work. Drill holes through the bottom of the table directly under where the miter is stuck, about 1/4 inch or slightly larger. Then oil it from underneath. After the oil has soaked for a few days try to knock it out with a punch through the holes that were drilled. Assuming that the operation is successful, you can chamfer the holes with a countersink drill bit so they don't become a snagging point.

drill the holes, but skip the penetrating oil and just use a punch and a hammer to push the stuck part out from the back side.. you might should be able to just drill one hole, close to one end of the stuck part... once it starts to move, it will come right out. if it doesn't move, use a bottoming tap to tap the hole(s) you drilled and use some good grade 5 or better bolts to apply pressure as you tap on the part with a real hammer from the top.. use a brass hammer if you don't want to damage it..

novaderrik wrote:

HappyAndy wrote: I think that the chemical based ideas are better than mine, but here is what I'd try if they don't work. Drill holes through the bottom of the table directly under where the miter is stuck, about 1/4 inch or slightly larger. Then oil it from underneath. After the oil has soaked for a few days try to knock it out with a punch through the holes that were drilled. Assuming that the operation is successful, you can chamfer the holes with a countersink drill bit so they don't become a snagging point.

drill the holes, but skip the penetrating oil and just use a punch and a hammer to push the stuck part out from the back side.. you might should be able to just drill one hole, close to one end of the stuck part... once it starts to move, it will come right out. if it doesn't move, use a bottoming tap to tap the hole(s) you drilled and use some good grade 5 or better bolts to apply pressure as you tap on the part with a real hammer from the top.. use a brass hammer if you don't want to damage it..

Dude, that is genius. If mapp gas dont work, this is the solution.

I wouldn't put too much heat in it, don't want to warp anything.

Got it. Combo of map gas and bfh.

Thanks for the help y'all.