We just had our hardwood floors refinished (and stained) with four
coats of oil modified urethane. Does anyone know how long it takes for
this kind of urethane to reach it's full strengh. I'm hoping to stay
off the floor until it's fully cured ... unless it takes months

Thanks,
Harry

A lot of manufacturers put a toll-free number or website on their products;
have you checked for that and given them a call? They'd probably be the
"experts" on how long things take.

Just a suggestion.

Clint

"Harry Muscle" wrote in message
ups.com...
We just had our hardwood floors refinished (and stained) with four
coats of oil modified urethane. Does anyone know how long it takes for
this kind of urethane to reach it's full strengh. I'm hoping to stay
off the floor until it's fully cured ... unless it takes months

Thanks,
Harry

Harry Muscle wrote:
We just had our hardwood floors refinished (and stained) with four
coats of oil modified urethane. Does anyone know how long it takes for=

this kind of urethane to reach it's full strengh. I'm hoping to stay
off the floor until it's fully cured ... unless it takes months
=20
Thanks,
Harry
=20

Oil/Varnish (urethane) finishes are Reactive Curing finishes -- they=20
bond with oxygen, or there is a catalyst in the mix -- so when the=20
thinner evaporates a reaction occurs... Cross-linking or polymerization..=
=2E


I suspect it is oxygen curing -- cures from the top down -- so If the=20
coats are thick (brushed on), I would treat it gently for a month... But =

that's an _opinion_ -- no facts to base it on till you give more info -- =

just a suggestion that has a wide safety margin.

You did not specify the brand or the exact type -- so at best people=20
could only guess -- since they have no info on the type.

You got some good advice to call the manufacturer, or look up their web=20
site -- since there is a fair bit of variation in curing times.

Get understanding Wood finishing by Bob Flexner if you want more detail=20
than you could ever wish for.


--=20
Will R.
Jewel Boxes and Wood Art
http://woodwork.pmccl.com
The power of accurate observation is commonly called cynicism by those=20
who have not got it.=94 George Bernard Shaw

"Harry Muscle" writes:
We just had our hardwood floors refinished (and stained) with four
coats of oil modified urethane. Does anyone know how long it takes for
this kind of urethane to reach it's full strengh. I'm hoping to stay
off the floor until it's fully cured ... unless it takes months

The label on your urethane will tell you.

I think the minwax oil based poly I used was okay to walk on in a day
or so, but no furniture for a week I think?

Best Regards,
--
Todd H.
http://www.toddh.net/

OK, I'm gonna try to call the manufacturer ... however in the mean
time, here's some more information I pulled from the MSDS ...

It's made by Torcan Coatings (www.torcancoatings.com) and it's called
Gymnasium Satin. It's an oil modified polyurethane from the aliphatic
hydrocarbon chemical family. It's 53% mineral spirts and 9% Silica
Amorphous. I'm not sure if this info actually helps anyone, but you
guys wanted more info.

Thanks,
Harry

It's not me doing the work, so I don't actually have the label from the
can ... so why don't I ask the contractor you say ... well, he does
great work, and at a good price, but there's a very big language
barrier which makes it hard to talk to him, not to mention the fact
that you can only reach him on the cell which cuts in and out making
things even harder.

Thanks,
Harry

Harry Muscle wrote:
OK, I'm gonna try to call the manufacturer ... however in the mean
time, here's some more information I pulled from the MSDS ...
=20
It's made by Torcan Coatings (www.torcancoatings.com) and it's called
Gymnasium Satin. It's an oil modified polyurethane from the aliphatic
hydrocarbon chemical family. It's 53% mineral spirts and 9% Silica
Amorphous. I'm not sure if this info actually helps anyone, but you
guys wanted more info.
=20
Thanks,
Harry
=20

From...
http://www.woodworking.com/wwtimes_oilvarnish.cfm

************************************************** ***
One very important factor when applying varnish is how the temperature=20
effects the speed at which it cures. You should not apply varnish in=20
temperatures lower than 65 degrees. If you apply varnish in lower=20
temperatures it may take several days, even weeks for it to cure. Room=20
Temp. (approx. 70 to 75 degrees) is good for applying varnish. Hotter=20
temps. will make the varnish cure quicker, but the solvent in the=20
varnish will evaporate quicker, making the varnish set-up quickly and=20
you may have a problem getting the varnish to flow out properly. This=20
could result in brush marks, bubbles and an uneven film. When working in =

temperatures higher than 75 degrees, try not to work on large surfaces.
************************************************** **8

Nobody seems to mention specific times -- because...

Temperature ***
Humidity
Thickness o application layer
and Exact oil/varnish ratio
sanded between coats?

all make a difference.

I stick with my guess of about a month for close to max. hardness. But=20
it's a _guess_

I am guessing that they brushed it on and had to work quickly -- so the=20
there was not much oil... It should dry harder if so.


Certainly no less than a week...




http://www.michaels.com/art/online/d...leNum=3Dae0119
"Let the varnish cure for several days before placing anything heavy on=20
it so as to prevent any dents being made in the finish. It is a good=20
idea to wipe a coat of clear paste wax on the bottom of any painted=20
object that is placed on the finished project, as this will prevent the=20
two sticking together."


http://www.google.ca/search?q=3Dvarn...3Dsxm&lr =3D=
&client=3Dfirefox-a&rls=3Dorg.mozilla:en-USfficial_s&start=3D10&sa=3DN


--=20
Will R.
Jewel Boxes and Wood Art
http://woodwork.pmccl.com
The power of accurate observation is commonly called cynicism by those=20
who have not got it.=94 George Bernard Shaw

"Harry Muscle" wrote in message
ups.com...
It's not me doing the work, so I don't actually have the label from the
can ... so why don't I ask the contractor you say ... well, he does
great work, and at a good price, but there's a very big language
barrier which makes it hard to talk to him, not to mention the fact
that you can only reach him on the cell which cuts in and out making
things even harder.

Thanks,
Harry


After a day you can start placing things, just be careful and no sliding.

"Harry Muscle" wrote in message
ups.com...
We just had our hardwood floors refinished (and stained) with four
coats of oil modified urethane. Does anyone know how long it takes for
this kind of urethane to reach it's full strengh. I'm hoping to stay
off the floor until it's fully cured ... unless it takes months

Thanks,
Harry

Many variables in that the curing is affected by temperature, etc. Most
will dry in 8 to 10 hours, but should not be really used for at least 24
hours. That said, I'd not move furniture back for about a week.