Removing bitumen from used oak blocks.

[diditmyself]

I ruined a couple of thicknesser blades trying to remove bitumen from reclaimed oak floor blocks.

Then I had the idea to set up the saw bench to do this instead by feeding the blocks through, on their side.
It seemed to work but, in spite of using water and washing-up liquid as a lubricant, it soon fouled the blade and I had to dismantle the blade and clean up.
The reason for the fouling is that bitumen gets soft when warmed by friction and then builds rapidly on the blade.
To eliminate this, I set the fence at an angle so the the teeth only were coming in contact with the bitumen.
I had made an opposite wooden safety fence to cover the blade and used a pusher to feed through.
It was easy to feed through 15-20 per minute.
I then realised that the blocks were being cleaned up at a slight taper because of the angle of block to blade and needed to feed through twice (to be very accurate with the dressing) I was probably too fussy.
The depth of cut clearly needs to be greater than the width of the blocks.

With the help of someone handing me the blocks and putting into sacks when finished. we were able to process 1250 blocks on a Saturday morning.

The blocks are not yet laid and I have a question, please.

Regarding the old varnish on the blocks, should this be removed first or will it be easy to sand afterwards, and which is the best kind of sander to use for a largish floor area?

 

[WoodYouLike]

:
The blocks are not yet laid and I have a question, please.

Regarding the old varnish on the blocks, should this be removed first or will it be easy to sand afterwards, and which is the best kind of sander to use for a largish floor area?

Interesting Saturday morning this must have been

As for your question: re-installing your blocks will give height differences between the various blocks so sanding has to be done anyway. Install all first and give everything time to bond properly to the underfloor before you start sanding.
Start with grit 40 to remove the old varnish layer and to level out the height differences between the blocks.
Than follow with grit 80 (collect the sand-dust if you want to fill any gaps between the blocks). When filling gaps: do that between this and the third sanding.
Depending on the finish you want to apply you need to sand again with grit 120 or 150. 120 for oil (hardwaxoil) finish 150 for varnish/lacquer finish.

Good luck

 

[diditmyself]

Thanks very much for your speedy and extrememly helpful reply.
Cheers