Trying to split some 2 piece BBS rims

Picked up a set of BMW Style 5/BBS RC090 rims from a junkyard for 200 smackaroos the other day. In good shape, just with a good layer of cheap black spray paint on them. So, I started cleaning them up, removed the perimeter bolts from one and started trying to remove the face from the barrel. I simply cannot get it to budge. I've tried about everything I've seen online: I baked it in my oven at 250 for 10 minutes, placed a folded towel and block of wood on the face and hit it with a 3lb blacksmith hammer until the wood split. I have a phone book there now, and I hit the edge with PB blaster and beat on it with the hammer again, and it just won't budge. From what I've read online, this is kind of normal. They're a pain to get apart, especially being 20-25 years old. I may just need a bigger hammer, but before I go out and buy a sledge I wanted to ask if anyone in here had any tips for splitting stubborn rims.

Have you tried driving a very thin putty knife into the seam, working all the way around?  Hammers can be a bad thing.

On the RC90s there probably isn't any room to do that.   

There isn't enough space for a putty knife. It's a very tight fit.

I have a phone book to protect the rim from getting hit by the hammer. On BMW forums they say you need to hit the rims very hard, harder than you think is okay, but it just feels risky to me. I'll probably just try to let some PB blaster soak for another day or two then go at it again, maybe with a larger hammer.

Heating the whole wheel probably expands the center as fast as the rim.   Like you, I watched all the videos on youtube that make it look easy.  Somebody must have used some really strong adhesive.

I'm almost thinking wet rags on the center and a torch heating the inside of the rim to see if you could get the rim to expand faster than the center.

But, i didn't sleep in a Holiday Inn last night.  All my experience is with 3 piece BBS...

One more caveat, I'm in a small apartment. So no torch, unfortunately.

What about tapping at one place on the center piece near the rim, and then working bit by bit around the rim, instead of big blows on the center?     Sort of like breaking the seal on Tupperware...

I tried some hard hits with the hammer/phone book combo around the edge, then back to the center.

One mistake I noticed was that my PB Blaster is their max lube, not the penetrating oil. I'm going to pick up some of the proper stuff tomorrow and let it soak for a day, then have another go. Hopefully the other rims don't prove to be this problematic. I've read about people using 2 handed sledgehammers with a phonebook to break these things loose, and I have to remind myself they came on a 4K pound car, so they can probably take the whacking I'm giving them without even noticing.

In reply to infinitenexus :

Does penetrating oil work on glue/sealant? I always thought of it, or at least only used it for rusty bolts/nuts. Maybe something like a stronger goo gone could work?

I see someone mentioned the putty knife, I was going to suggest a razor blade....might be a touch thinner?

I took a set of RC090 wheels apart to prep them for polishing by driving the bolts out first.  I used a block of oak so I didn't damage the threads.

Turn the heat up, 250 ain't doing it, turn it up to 350, Aluminum sucks up heat, more heat or more time.  

In reply to benzbaronDaryn :

350 degrees for 10 minutes and about a dozen hits as hard as I could and it finally split. Thanks!

Interesting.  I'm on the fence to buy a set of cool multipiece wheels for rabbit.  Most will need a refurb due to age.

will this work ?

take a putty knife and heat it up on the stove  , try and  get a 1-2 inch slice all the way to the center , 

then take a knife , heat it up and  put it in the cut out area and pull it to the side ,

I have a set of 8 and 9 inch 3 piece BBS that I might take apart and narrow some day.....

In reply to californiamilleghia :

They fit way too tight to get a putty knife in there. Honestly a razor blade probably wouldn't even fit.

But heating them for 10 minutes at 350 degrees, placing them on the floor on a towel, placing a phone book on the face of the rim, then whacking it as hard as I could a dozen times with a 3lb hammer finally worked. I was concerned about hitting the rim this hard, even with the phone book, but as I read online these are forged rims and can take a lot of abuse. Plus, my 3lb hammer isn't going to stress them as much as a 4K pound car.

You are overthinking it, hit it harder.

Really.
 

I use a 2x4 and crack it with a 4# hammer and they come apart. 
 

Edit: missed that you got it. 

Found some spare time so I started on rim #2. Soaked it with PB blaster, where the two pieces fit, twice. Baked it at 350 for ten minutes, whacked it as hard as I could, and nothing. All I can figure is I need a bigger hammer. I am a very strong person, and wailing on this thing with a 3# hammer does nothing. So I guess back to home depot to get something bigger.

Repeated heat cycles, and chill the center with a wet towel under the phone book as you prepare to beat. Do not exceed 350f.

Have you removed the bolts first before trying to pop the center out of the rim?  I found them pretty easy to separate once the bolts were out.

Yeah I removed the nuts and bolts around the perimeter. This rim is just really stuck in there. From some reading on the interwebs, these rims seem to be notoriously hard to separate. Although maybe that's all multipiece rims.

Either way, I'm going to pick up a bigger hammer after work today. 

If it was me I would spend the bucks on a MAPP gas torch (since it is handy anyway) and rig up a turntable like an old Lazy Susan to rotate the wheels,  then I would heat the barrels right at the point where the inners and barrels meet.    That should keep the centers reasonably cool and consistently dimensioned. That would also have the advantage to breaking down any sealant that may be in that area.

Then hammer away.  

Alternative answer is find someone with a big shop press and have at it.  

My only issue is that I'm in a small apartment, so the gas torch thing isn't really an option. Finding a place that restores rims is an option, and one I should probably consider.

Went and bought an 8 pound sledgehammer and gave the rim a few test thwacks. nothing. I'll try heating it up today or tomorrow and beating on it. If that doesn't work, I'll just find a rim place.

In reply to infinitenexus :

I'd just find a rim shop, that way if they break it it's on them.  Besides, they have the tools and the talent.  Pay the man.

Put it in the oven at 350 for 15 minutes, then beat on it with an 8 pound sledge. After about a dozen whacks it finally broke free. These things are crazy stuck together, but I remind myself they were built to withstand the weight of an E39 hitting potholes. once I seperate them all, I'm going to clean them up a bit and take them to a rim repair shop to get powder coated.