Rok-Block removal

[Chipped tooth]

Has anyone came up with an easier way to remove block fill yet?

I have a block that the filler is falling apart on and need to refill it... maybe...

Judging by the way the filler looks compared to other filler I've used I'm leaning towards Rok-Block was used.

There was a post i found that Cement off was supposed to work but he never updated his post...

[rebelyell]

Never tried so Don't know
Perhaps some machine shops' bake n blast might clear block fill ? Dunno?

[BillK]

Perhaps some machine shops' bake n blast might clear block fill ? Dunno?

Nope, At least mine wont. Just turns the top layer into dust and makes a mess in the blaster.

[Chipped tooth]

Looks like it's back to the hard way again.

I was sorta hoping someone came up with something by now.

I'm guessing antifreeze is what broke this stuff down.
I can't think of anything else that would cause it to start coming apart.

[1972ho]

Just look at how they have to get it off building and bridges should give you some idea how to get it off.

[af2]

Sulfamic acid is used for grout and found at most hardware stores.

[amc fan]

I wonder if the Metallaxx process would work for removing/breaking down the Rok-Block.

[Chipped tooth]

I put a couple chips in an small aresol can cap then put a few drops of muriatic acid on and left it outside over night.

Well I had 2 chips left but smaller and goo in the bottom of the little cap...

Not sure what I'm gonna do because some is soft and breaks out easily and some is hard like it's supposed to be.

Maybe a 55 gallon drum of lye?
Let er soak for a while...

[dfarr67]

I think we used to use muriatic acid to clean material (concrete) testing tools including cast aluminum.

[Chipped tooth]

Muriatic acid and aluminum is a no no for anything other than a quick cleaning.

Works great as a crusty carb flush too as long as you have the garden hose running right by.

It removes iron too just takes longer to eat away.

[Chipped tooth]

I wonder if phosphoric acid would hurt cast iron?

I noticed my go to for radiator flush is phosphoric acid.

Better known in the farming community as milkstone remover.

[rustbucket79]

Why not just remove the loose stuff and pour a skim coat if you’re concerned, or just run it as is.

[Chipped tooth]

With the current fill crumbling if I just try to patch it I'll have issues sooner than later.

If the block didn't have so much work done to it I'd just use another.

But that's what I'll probably have to do, remove as much loose stuff as I can then acid wash and pour it again...

Pull the pin and wait...

[Chipped tooth]

I tried milkstone remover using the chip method again.

Seems to be attacking the iron more than the fill... so that's not gonna work either.

[Bill Chase]

Maybe some kind of resin to lock it in place and seal it up at the same time?