Rok-Block removal

[BillK]

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.

I would bet it was mixed too "wet" when installed. Concrete does the same thing if you pour it too wet. After a while the top layer starts breaking apart.

[Caprimaniac]

How about ultrasonic sound- waves?
Powerful enough, it’d bresk the fill away from the block wall & crunch the stuff, leave the iron alone?

2 cents onnresin to cover up...
I think you will not be able to get it all out. Althogh, I never gave it a go, so- who knows?

[Chipped tooth]

Billk you're probably right!

I think what I'm gonna do is remove as much of the crumbling fill then acid wash and let dry good.

Thinking I might use fiberglass resin to fill about another 1/2" or so.

Anyone use fiberglass resin to fill before? Issues? Better idea?

I've used it numerous times to fix rusted out fuel tanks on small equipment, motorcycles ect.

[mt-engines]

Billk you're probably right!

I think what I'm gonna do is remove as much of the crumbling fill then acid wash and let dry good.

Thinking I might use fiberglass resin to fill about another 1/2" or so.

Anyone use fiberglass resin to fill before? Issues? Better idea?

I've used it numerous times to fix rusted out fuel tanks on small equipment, motorcycles ect.

Rokblock is meant to be mixed almost like pancake batter. if not enough water is used, it will crumble.
phosphoric acid will convert any rust in the block but not do anything really to the rokblock.
i would just chip it out and seal it with an epoxy, or another 1" layer of rokblock.

if its already a tall fill, block half the waterpump hole with some gorilla tape and pour it till it about comes out. then when it dries you can port it.

if you are only using water the Fiberglass resin should work fine. as far as with coolant, i am not sure. i have only used it with straight water before without issue.

[Chipped tooth]

Update on my Milkstone remover test.

The fill piece turned into mush, completely broken down.

The iron piece doesn't look to bad but it's black...

My jug says mixture of phosphoric and sulfuric acid, my jug is probably 4-5 years old.
The msds states phosphoric acid only.
I might look at current jugs on the shelf and see what it states for ingredients.

I'd say Milkstone remover works better than hydrochloric acid, hydrochloric still left sold pieces but smaller.

Thank you everyone who has commented!

I appreciate the help!