Age old Q parquet /bitumen removal

[Tigercubrider]

Yes I have looked and much of the info is quite old.
I have done a small amount before but want to DIY a semi industrial method to speed it up.

in the past I have used white spirit to soften the bitumen on some recycled blocks.
I also did the freezer and chip method.

I have about 300 blocks to do.

my plan is to remove as much bitumen as I can by some method before using a thicknesser to standardise the blocks. The thicknesser is nearly brand new and belongs to work so I can’t use it for the bitumen removal for fear of covering everything in gunk.

Has anybody managed to develop a technique that was efficient?

one idea is to modify my black and decker electric plane that hardly gets used to become a semi thicknesser. Possibly upside down (in a frame) to mechanically remove the bitumen. My fear is that the blades will heat the bitumen and not work. The plane is able to be sacrificed if it works.

option two is to use the good old manual scraper but make a sort of 4 wheeled dolly to get the 20mm block fit under the hand scraper blade.
i could make sort of tracks /guide rails for the wheels and pack the height.

option three is the nylon paint stripping discs, used to remove paint from metal. Angle grinder used, maybe generates heat?

I could try the solvent route with white spirit /paraffin. This takes time to work, May be actually quicker than mechanical means, given the construction time.

if I could obtain some liquid nitrogen (!) or dry ice (more likely) I have seen a guy lay dry ice on a car floor in order to freeze the sound deadening bitumen and then hit it with a hammer to break it. I do know about dry ice blasting but not possible.

last option is a paint shaver? I only discovered this yesterday. £200+ but potentially quick. It is basically a milling machine made to remove tiny amounts and therefore a tiny amount of wood also.

thanks!
i can live with mind numbing tasks but a bit of speed would help

 

[Deleted member 174758]

Lift it by breaking-out with the biggest pry bar you can get your hands on - I have a 36in forged bar plus a couple of Burk bars (concrete form work dismanyling bars, 54 and 60in respectively with curved ends, which a buddy fabricated for me - Marshalltown do sell them, but they are over £100 each which is why I had a couple made). They all need sharpening to a blunt point if that makes sense

In the first instance I chip the hard bitumen off the backs of the released blocks by hand with a lump hammer and an electricians bolster. It is a thankless task. The best solvents I've found are probably red diesel or paraffin, but both are smelly, not good for the environment and take relatively ages to work, so retain for cleaning your tools up

After hand cleaning I rip saw the bottom edges of the lifted blocks to take the rest off using a portable table saw (the upper faces are run against the rip fence) - last time I did this I hired a portable table saw and got in a goodly supply of cheap TCT blades rather than wreck my DW saw. This uses a lot of blades and it is highly advisable to build some form of oversize shield above the blade to protect yourself from flying debris, as well as to make up a number of sacrificial push sticks, 16 to 24in long, as you'll get quite a few kickbacks! This is a filthy task: it generates lots of nasty black dust (P3 mask and coveralls required) - so best done outside on a protected surface as the dust will get into pores in unsealed surfaces such as limestone paving. At the end of a day doing this you can end up resembling a collier coming off shift, depending on the bitumen. You just have to accept that the hire company will bill you for clean-up of their saw as you can never get them 100% clean

Bitumen is horrible stuff to deal with and when fully set it will devour tool steel and HSS cutters, such as planer blades, for fun. When warmed it will clog everything it touches and set quite quickly, so you need to work fast with it and not get it too hot because it is then almost impossible to cut (although it will scrape off with a Linbide type floor scraper), so planing or abrading it in any way is normally a no-no as those sorts of techniques warm it up. I think you'll have problems with a paint shaver - i am certain the Metabo and Porter-Cable types I've seem in the past which use carbide or diamond coated cutting heads would run hot quite quicklyand just end up clogging. Definitely a job to do on the coldest of days, although liquid nitrogen or dry ice might speed the process up!

I am currently setting up to do another job like this in the near future (about 1200 to 1500 blocks, some of which are damaged and need to be replaced) where an oak parquet floor must be lifted, the sub floor raised and then relaid about 25 to 30mm above the original level to match the floor levels of several adjoining rooms that the owner has had engineered flooring installed in

As far as I can see this isn't ever going to be a quick job - it certainly isn't a clean job - which is why the parquet guys charge so much for it (mine is part if a package of work - you sometimes have to take the rough with the smooth)