Stripping polyurethane off a timber floor

[depreciator]

It's a pine floor - cyprus, I'd say - and the poly would have been down at least 15 years.

I want to stain the floor really dark brown - almost black. (I know, I know, this will horrify people who crave the polished pine look, but pine is pretty boring.)

The poly is really hard - whoever did that floor did a bloody good job.

I don't think paint stripper would be appropriate. Is there a 'poly stripper' I can use to knock off the gloss before I give it a bit of a sand?

Scott

 

[Peter 14.7]

Just sand it Scott.

Stripping is messy, as you get gunk everywhere that sticks to everything. Sanding means neat dust in a bag you can trow out in one go.

I know a good sander but I suspect you are hands on.

Regard Peter

 

[depreciator]

It's a tough room to sand - joinery around three walls nearly finished (I put that in before we decided a dark floor would look better).

I'll be doing it by hand with a Festool ROTEX RO 150mm sander, which aficianados of sanders will know is an amazing thing.

Getting the gloss off chemically will help.

 

[willair]

You could always try Oxalic acid i use it on antique tables in the restoration ,and just about every hardwood floor i have ever fixed up..
http://en.wikipedia.org/wiki/Oxalic_acid

 

[depreciator]

Not sure about oxalic acid. It's good for bleaching or cleaning timber, but I don't think it would shift poly. I'll investigate.

 

[mikew]

Just a guess, but it could possibly be extremely hazardous for your health. I remember hearing that polyurethane is full of all sorts of carcinogenic nasties.

 

[arms]

Just a guess, but it could possibly be extremely hazardous for your health. I remember hearing that polyurethane is full of all sorts of carcinogenic nasties.

polyurethane is a two part system consisting of the main base coat and a hardener to activate the acids to make it go hard ,when hardened it is no more dangerous than any other floor coating ,sand it back with a good sander with efficient dust collection and it will be fine

 

[vaughan]

It's a pine floor - cyprus, I'd say - and the poly would have been down at least 15 years.

I want to stain the floor really dark brown - almost black. (I know, I know, this will horrify people who crave the polished pine look, but pine is pretty boring.)

The poly is really hard - whoever did that floor did a bloody good job.

I don't think paint stripper would be appropriate. Is there a 'poly stripper' I can use to knock off the gloss before I give it a bit of a sand?

Scott

Have you looked into Japan Black instead of stain? It might be able to go right over the existing poly.

 

[pinkboy]

Just a guess, but it could possibly be extremely hazardous for your health. I remember hearing that polyurethane is full of all sorts of carcinogenic nasties.

Isocynates!

Really nasty $h!t.

It can affect you from one bulk dose, to slowly kill you over time when your body sensatizes itself from it.

I have for the past 9 years sprayed 100% solid polyurethane and polyurea coatings and foam. These plural componant polys consist of 50% pure isocynates, as opposed to between .1 to 10% in polyurethane paints and clears.

Needless to say, I get very irritable when I spray these types of coatings, both respiritory and dermal problems, and have to cover up and use full breathing apparatus due to my body reaction to iso.

Did I mention it is really nasty $h!t?

Oh, and when most products are reacted off (with their respective resin polymer), they are generally potable water rated - so you can litterally eat off the products !

pinkboy......nasty $h!t

 

[TONKA]

you need to sand it and if its much bigger than a few square metres its going to be a pain in the **** using only an orbital sander. i also have a R0-150 and as good as they are they arent designed for stripping large areas of poly thats why drum sanders were invented. just remember when you stain you need to sand the area ultra fine to avoid high lighting your sanding marks too

 

[depreciator]

That's not wanted I wanted to read, Tonka, but given your signature it may be what I need to read.
With the joinery in, I'm down to about 22sqm. I suspect I won't get somebody interested in coming and doing that - I'm in Sydney, remember.
I would have enough 40 grit discs.
Sigh.
I have a young bloke - son of a friend - who might be up for some pocket money.

About the stain, I'll be using a mix of F&W prooftint - black and brown mixed give me the colour I want (I've done a test). Is it possible to buy that in bigger quantities than the cans Bunnings sell?

Not sure what I'll put over the top. I like the feel of Osmo Hardwax Oil. Crazy price though - $190 for 2.5 litres.

 

[TONKA]

With the joinery in, I'm down to about 22sqm. I suspect I won't get somebody interested in coming and doing that - I'm in Sydney, remember.
I would have enough 40 grit discs.
Sigh.
I have a young bloke - son of a friend - who might be up for some pocket money.

40grit discs will be ok to get the poly off but if the young bloke has poor attention to detail he will probably miss some bits that will show up later through the coating also if you are staining it you will need to work up through the grades to 120-150 grit minimum so you need a lot more sandpaper. if you really want to do it yourself go get a drum sander and edger from bunnings you'll save yourself a hell of a lot of work but seriously if you are talking direct stain and wax finishes it sounds like a job left to the professionals, ring around i'd be surprised if no-one would do it

About the stain, I'll be using a mix of F&W prooftint - black and brown mixed give me the colour I want (I've done a test). Is it possible to buy that in bigger quantities than the cans Bunnings sell?

yes. i get mine in 1 litre cans from a floor sanding supplies store but im pretty sure a lot of paint shops will stock it in this size.

Not sure what I'll put over the top. I like the feel of Osmo Hardwax Oil. Crazy price though - $190 for 2.5 litres.

ive never used that so i cant really comment on it. for wax i use this stuff: http://www.whittlewaxes.com.au/

its about $170 for 5 litres from memory

 

[fernfurn]

Why dont you mix dark brown/black paint into a new clear topcoat and recoat over existing.

 

[TONKA]

Why dont you mix dark brown/black paint into a new clear topcoat and recoat over existing.

you CAN do that but there's a fair chance that the new coat may react or not adhere to the old coat. do you know that the old coat was single or two pack poly, waterbase or oil? have any cleaning products been used on the floor? has anything been spilt on the floor that may react or contaminate the new coat? most floor sanders wont go near a request like that or will charge big $$$ because of the risk involved even on a small job

 

[TONKA]

also the depth of colour when tinting the top coat will be nowhere near when direct staining it to raw timber

 

[depreciator]

Thanks again, Tonka.
I won't be putting a coat over the poly. I know that would end in tears.
The floor will be stained with a mix of F&W black and teak brown. It produces a very, very dark brown - almost black. I've done a test. I've got paper in varying grades, so that will be okay for the scratches. But equally, with a colour that dark scratches are not really going to show up. (Well, they didn't in my test bit anyway.)
All the edges are done, so it's just a job for a drum sander. I had a bad DIY experience with one of those - ended up with deep furrows across the floor, though admittedly it was a softer floor than the current one. (A mate of mine had a worse DIY sanding experienc). I'll see if I can find someone interested in doing a small sanding job.
Whittle sounds a lot cheaper than Osmo. I'll ring around.

You'll appreciate my mate's DIY sanding tragedy, Tonka. I've told it before, but it's worth trotting out again. My mate Matthew is hopeless at anything DIY. He and a mate were given the task of sanding the floors in the family holiday home. It was a little fibro house up the coast. They parked their car beside the house, lugged the drum sander inside and put the paper on. I can't remember which one was having the first go, and whether it was before or after the first beer, but he turned it on, lowered it to the floor, and it took off. It flew across the floor, through the fibro wall, and onto the car. I think they just quietly packed it all up then and went home.

 

[TONKA]

You'll appreciate my mate's DIY sanding tragedy, Tonka. I've told it before, but it's worth trotting out again. My mate Matthew is hopeless at anything DIY. He and a mate were given the task of sanding the floors in the family holiday home. It was a little fibro house up the coast. They parked their car beside the house, lugged the drum sander inside and put the paper on. I can't remember which one was having the first go, and whether it was before or after the first beer, but he turned it on, lowered it to the floor, and it took off. It flew across the floor, through the fibro wall, and onto the car. I think they just quietly packed it all up then and went home.

wow thats crazy! ive heard of it happening before and usually involves a hole in a wall but not into a car. that story made my day

 

[namtrak]

Get a pro in. Staining is quite difficult to get right and using the Festo will make a mountain of dust. Also being in Sydney, you are in the right market as a buyer of floor sanding services - cheapest place in the country

 

[depreciator]

the Festo will make a mountain of dust.

No dust given I've also got the attachable Festool dust extractor (otherwise known as a fancy vacuum cleaner) that comes with a breathtakingly expensive reuseable bag - over $400 for just the bag.

I'll have to wait till January to get a floor sander guy - I'd say they would all be pretty busy now.

Thanks,

Scott

 

[melbmeg]

You won't listen to this, but...

DON'T DO IT!!!!!!!!!!!!!!!!!!!!!!!

A few years ago I sanded my floors and stained them with a lovely black/brown mix. I am now in the process of going back to a mid-depth colour. The dark colour is elegant but the maintenance is horrendous. A small hair ball or a crumb is visible for miles. If you are a bachelor with OCD, maybe. If you have kids or a messy partner, do not even think about it.

Everyone told me not to do it and I ignored them because I'm all about STYLE. Not any more.