Cleaning up reclaimed Parquet

[Petey83]

So following on from my last thread I am now the owner of 70 plus sq mtrs of reclaimed pitch pine parquet - well over 2000 blocks I reckon.

Some of it is split / chipped on the show side but I suspect I can repair if needed and it all adds to the aged feel of it.

My issue is around removing the old bitumen on the backs. I was originally planning to use my multi tool to scrape the backs but the number of bricks I have to do will make that very slow and I'll likely kill my Multimaster in the process.

So my thinking has turned to two different approaches.

Option one is to grab a cheapo Titan PT from Screwfix and use that to clean the backs off and then thickness all the blocks to ensure uniform size using the show faces as reference.

Option two is to get a cheapish table saw, something like the evolution fury one and use the show side as reference against the fence and just cut 3-4 MM of the back of each block.

Appreciate either method won't give me perfectly uniform thickness over the entire load but given the flor will be sanded in situ after laying I'm not to worried about a MM or 2

Any other suggestions very welcome

 

[Rorschach]

Table saw method is the one I have heard is fastest, easiest and gives good results as long as your blocks are still fairly thick.

 

[Petey83]

Table saw method is the one I have heard is fastest, easiest and gives good results as long as your blocks are still fairly thick.

Ive not measured the thickness yet but they are easily 20mm plus thick with some being a lot thicker. It was quite interesting looking though the bags last night as you can see where some blocks were made on site to suit the floor. It's over a hundred years old!

 

[wallace]

Don't bother putting them any where near a p/t until they are clean, the blades wont last 5mins. Tried it last year. Also don't put them through a bandsaw, they trash blades on them too. I did mine on the saw bench, I used the finished side against the fence and then I cleaned up an edge. I then planed those two faces and then had a good reference to put through the sawbench again to clean up the other faces. It makes it a doddle for when you come to laying them. I only needed a quick finish with the ROS when they were layed. Its really messy so plenty of ppe is needed.

 

[Jake]

If it is tongue and groove, the trouble with anything referenced off the top face is that there is often a big difference in the thickness of the 'tops' above the tongue where different bits of flooring have been sanded different number of times etc. On the one I am doing now, the thinnest are about 8.5mm above the groove, the thickest about 14mm. And, what's more, the thickness on each corner of some individual blocks can also vary from 9mm to 13mm - presumably originally laid skew-whiff before being sanded flat.

What's the bitumen like? If it is solid and even it can be left on with the right adhesives. The one I am doing now was really thin but very brittle so I spent a few days in the garden with some Romanian chaps scraping it off with Bahco scrapers. Only takes 30 seconds per block (and about the same doing the t&g) but it all adds up when there are 4k blocks or so.

 

[No skills]

Maybe carbide scraper as mentioned.
Or an angle grinder with 24 or 36 grit sanding disks on it, if the tar is thin you should get a few blocks done with each disk - if it's thick forget it.

 

[Petey83]

If it is tongue and groove, the trouble with anything referenced off the top face is that there is often a big difference in the thickness of the 'tops' above the tongue where different bits of flooring have been sanded different number of times etc. On the one I am doing now, the thinnest are about 8.5mm above the groove, the thickest about 14mm. And, what's more, the thickness on each corner of some individual blocks can also vary from 9mm to 13mm - presumably originally laid skew-whiff before being sanded flat.

What's the bitumen like? If it is solid and even it can be left on with the right adhesives. The one I am doing now was really thin but very brittle so I spent a few days in the garden with some Romanian chaps scraping it off with Bahco scrapers. Only takes 30 seconds per block (and about the same doing the t&g) but it all adds up when there are 4k blocks or so.

Yea I was a bit Worried about the T&G but my fall back plan was to secret nail it if I had to as I I've seen a blog about that a while back.

It's all come from a school hall so expecting wear to be nominally the same

The amount we have to do there is no way me and the missus will do it by hand as it's pretty solid and thick

 

[Corset]

Metabo do a paint stripper that would do the job. It got a rotating cutter block to strip a thin layer off. I only know about this because I bought one recently at an auction and had a play with it. Metabo lf724 is the new model.
Might be a midway solution. It's for sale now but this is not an advert, it just a tool I never knew existed.

 

[bucephalus]

My brother bought a load of reclaimed parquet that was covered in bitumen on the bottom and sides/ends, and a horrible mix of adhesive and carpet remnants on the tops. We set up a production line in my workshop to clean them up (filthiest job ever). First my brother got the worst lumps off and knocked out any splines that were still in the grooves with a hand scraper. I then cleaned the long edges with three or four passes on my router table until we had clean wood on both long edges, then the sister-in-law sanded the ends until they were flat/clean looking using a jig with a belt sander that I set up so she could do it safely. We didn't even touch the bitumen on the bottoms unless it was really gnarly - the adhesive he laid them with didn't have a problem with them having bitumen on them. Then of course once they were laid they had to sand the floor (a lot) before sealing. We found that getting the sides really clean and the ends more or less clean worked for us because they wanted them laid in bond pattern, and once cleaned they laid together really well. Came out great in the end, but a filthy, filthy job... went through about 4 router bits but it was the quickest and easiest way I could think of. Had to buy some tar cleaning stuff (can't remember the name) to clean up my router table.
Good luck!!!

Cheers

Gavin

 

[Petey83]

The blocks we have are a real mixture but most seem to be quite heavily tared and even have concrete still on them.

My router table is unfortunately a Festool CMS with OF1400 fitted so I'm reluctant to use it for such dirty work but it may be a good idea for skimming a mil of each side so the fit nicely.

I've ordered a Dewalt DE745 as had some axon vouchers going spare and thought it would have a half decent resale value should I chose to love it on once the deed is done.

First job will be to start sorting the blocks into grades as a I expect a lot to need some sort of repair to small surface splits and some will just be going in the incinerator.

 

[graduate_owner]

I have some of these pitch pine blocks, again from a school and over 100 years old I think. I was wondering if the tar, which is really thick and stuck with grit / lime on some, could be removed with a scabbler. I bought an electric hand held scabbler from fleabay some years ago to clean up a concrete floor, it has a rotating cylinder which has rotating hardened steel teeth ( a bit difficult to describe). I thought to clamp a number of blocks together to be able to clean up a large area, say half a square metre. Then I could use the cleaned bases as a reference surface. I haven't tried if yet though, it is a daunting task.
Then there is years of polish on the top side, which clogs abrasive paper when cold and turns into chewing gum if heated. I don't want to use the scabbler on it because it is the finished surface and the scabbler will probably cause too much damage and will need loads of sanding.
Finally there are the 4 sides which are absolutely thick with years of dirt and will need to be cleaned if they are to fit closely, but also kept flat and parallel so I am not sure about sanding. Sawing would be an option but would make the blocks smaller, obviously, so will need to be done carefully to ensure the blocks all remain the same size and fit correctly when laid.

As I said, it is a daunting prospect, and there are about 50 blicks per square yard, more if I cut the sides. No wonder I haven't tried it yet!! They might end up being cleaned, glued together and put on the lathe. That would be a case of cleaning up only about 4 at a time.

Anyone want to buy about 18 or so square metres of dirty blocks?

K

 

[n0legs]

Hire a floor sander and get the coarsest belts available.
Get a piece of sheet material, ply, c/board, mdf, doesn't matter which.
Screw down some battens at the edges on three sides.
Lay the blocks, as many as you can fit, glue side up and wedge them in with a forth batten.
Sand the blocks, repeat until all are done.
Quick and easy.

 

[bucephalus]

My router table is unfortunately a Festool CMS with OF1400 fitted so I'm reluctant to use it for such dirty work

Absolutely - mine was just a cheap one, don't use any nice tools near this stuff...

 

[Alexfn]

Dont attempt any of the sanding methods mentioned especially the floor sander one. All that will happen is the bitumen will melt in seconds and clog the sand paper.

I have a copy of the metabo machine mentioned. Im not sure that will work either but the copy is only 80 quid. I will try find a link

 

[Dan j]

Sika make an adhesive which works on blocks with bitumen on them.
As long as there's not too many lumps of gunk on the back.
The solvent in it melts the bitumen and then sets.

 

[Petey83]

Took delivery of a Dewalt DW745 today in order to do this job. Didn't fancy using my Festool CMS With my TS55 inserted for a job like this. Had some Amazon vouchers that covered a bit of the cost so not to bad on the pocket.

Have to saw the saw is impressive for the money and it's something I'll be keeping for rougher work before moving into the CMS system.

Decided on this as a lot of the bricks are different thicknesses where they have clearly come from different parts of the floor - guess the Edwardians didn't do floor levelling to well... Knocked the worst lumps of concrete off the back and then set the saw to 20mm and pushed a few blocks though. Results were good on the few test blocks I did and I have 4 clean bottom 20mm blocks now.

Only thing I'll need to do before going into full "production" is make a zero clearance throat incert as the thin slices coming off the back are a real flying kick back danger with a table saw and would really slow down my workflow having to stop and start the floor after every block or two in order to move them.