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Refinishing an old shellac floor

cank's picture

I need some advice and after looking through a lot of old posts, I still need some help.

I am trying to refinish some red oak floors that are 50+ yrs old. They spent a long time under carpet and have some trouble spots, like dark splotches, areas without any finish, cupped boards, etc... I have learned that they are shellac and I don't think they have any layers of wax on them. I am wondering if they have some sort of stain because in some spots that I had to repair and sand down to new wood, when I brushed on 2 coats of Zinzer Amber shellac it doesn't quite match. Could that just be the age of the wood and not a stain?

Some more questions and info. The front two rooms had been previously refinished with Polyurethane and the color matches great where the two finishes meet. Would I be better off just using a drum sander (I think I would have to sand too long with a random orbital because of the cupped boards) and matching the front rooms? The Dark spots in the finish are kind of like scabs, I can use a putty knife to scrape some of it off but they go completely through the finish to the bare wood and I can only get them out by dabbing Denatured Alcohol on the spot, letting it soak in, and then wiping it vigorously. This of course leaves a ring of unfinished wood that I have tried to brush over to make it disappear, but cannot seem to make it blend in.

Also, I have been trying to find amber shellac in gallons but no one seems to carry it. Would I be better off mixing my own shellac (sources anyone?)? What did they do back in the 50's? What kind of advice do you have for application?

I know it's a lot but I feel overwhelmed right now...
Thanks,
Marc

frenchy's picture

(post #112381, reply #1 of 63)

Drum sanders really need skill to operate well.  Gouges are the most common problem  but you can also get wavyness and other problems caused by a lack of skill and experiance. Dark stains are most likely the result of water damage. a cat might have peed there or a plant was watered there etc..


  If the wood is too badly cupped you may not be able to save it.  You can only sand off about a 1/4 of an inch before you start exposing the spline or get the wood too thin so the spline splinters out..


 Blending shellac IS SIMPLE IF YOU THIN IT ENOUGH. 


 Zinssler's sells shellac in gallons and most big box stores have it as well as some large paint stores.


 Plastic er polyeruthane absolutely requires sanding to repair and you cannot sand part  it has to be the whole floor.


  To get amber from ultra blond you can mix some garnet flakes untill it matches.. make sure you add a lot of denatured alcohol or it becomes too thick to apply nicely. Flakes are more than 2times  you follow the directions on the can.  That plus it takes a lot longer to dry.


  I commonly use 2 gallons of denatured alcohol to one gallon of Zinssler's  for floors.  it's really tough to skillfully apply shellac fast enough to keep a wet edge on it if mixed according to the directions on the can..

cank's picture

(post #112381, reply #2 of 63)

to get it to blend is it just a matter of putting on enough layers? Will it not make the existing layers darker?
The boards are not that cupped, just slightly. I would rather not sand if I don't have to.
I can find the clear in gallons but not Amber. Guess I might have to buy some flakes on-line. What are some good sources?

I also need to match some aged pine trim. I have looked through the posts and watched Hand Applied Finishes: Coloring Wood with Jeff Jewitt who used nitric acid to age pine but I feel a little cautious about that method. Looking on knots, someone mentioned using tea. What would be the process if I was to use tea to "stain" pine and then finish it (probably with shellac).

Thanks,
Marc

frenchy's picture

(post #112381, reply #6 of 63)

New shellac melts old shellac. That's what gives you invisable repairs.. that's also why you need to use thinned shellac so the denatured alcohol has enough time to melt into the old finish in order to blend.


 When I've bought flakes I've purchased them locally from places that specialize in working with wood. I hate it because flakes are so much more expensive than gallons of Zinssler.Plus they take fussing with in order to get them fully mixed.. I used to use a morter and pedistal to crush them into powder but I've heard of using a coffee bean grinder to achieve the same thing (I don't know how well that works) 


 The other thing is too often the flakes have been sitting on a shelf for too long and that results in a sheelac that doesn't dry properly.   


 I've sanded my own floors with those square pad sanders  (actually rectangel shaped, about 20"x24" )


 My floors were a real mess because I had the planner set at slightly differant thickness everytime a spent a day making flooring. some of the differances in thickness were as much as a 1/4 inch.  It took me about 6 hours to level out about 1000 sq.ft.  (ask I'll give details about how to do it) 


 I didn't have any risk of sanding to the spline because I put the spline down towards the bottom and I Only planned one side so I had over 7/8ths thick wood with more than 1/2 inch to the spline.(that's what you can do when you make your own flooring from rough sawn lumber)


Edited 7/11/2009 11:59 am ET by frenchy

cank's picture

(post #112381, reply #7 of 63)

When applying shellac to a floor what is the best method? Lambs wool pad like for poly?

frenchy's picture

(post #112381, reply #8 of 63)

That works well and I wish I could remember to buy one..


  I have an old barn paint'in brsush that I use but that's dumb the lambs wool applicator would get me off my knees. I have in the past when I forget the brush applied it with my T shirt.


  The trick is don't paint it on, flood it on!  Heck if I had a cotton mop I'd use that..

Gretchen's picture

(post #112381, reply #3 of 63)

You need to just start over --sand and stain and refinish with poly for better wear. The dark stains could be pet urine through the carpet.

Gretchen

Gretchen

SteveSchoene's picture

(post #112381, reply #4 of 63)

In the current housing slump, you may well find pro's who would jump at the chance to sand the floors at decent prices. 

Test your finish on scrap, FIRST, or risk having to scrap your finish.

cank's picture

(post #112381, reply #5 of 63)

I have called a few places and I either get no return call or they don't refinish floors. I would rather do it myself anyway.
As for the dark spots they are all small, about the size of a pea, and the room was used as an office (read party room) so it could be alcohol.

Thanks for the replies.
Marc

woodguydan's picture

(post #112381, reply #10 of 63)

cank, about the size of a pea you say?is it strip flooring which was top nailed? because it sounds like water stains from the carpet being steam cleaned.this is very common ,also how do you know it is shellac? and are you sure it is not white or brown oak? because 50+ years ago both red oak and shellac are unlikely.

Dan

frenchy's picture

(post #112381, reply #11 of 63)

Dan shellac was the most common finish for flooring untill post WW2 with the advent of new wonder plastics that were supposed to be better.


 (they aren't but I digress)


 The test is so easy that a caveman can do it! 


    My humble apologee to all cavemen  <grin>

woodguydan's picture

(post #112381, reply #13 of 63)

frenchy, 50 years ago is post WW2

frenchy's picture

(post #112381, reply #15 of 63)

yes!  Your point?

woodguydan's picture

(post #112381, reply #17 of 63)

and your point? other then insulting cavemen :)

frenchy's picture

(post #112381, reply #19 of 63)

Well I feel relatively secure since cavemen don't use computers  <grin> 


 However if you bend over with a rag soaked with denatured alcohol and rub briskly you can tell if it's shellac in 30 seconds.  No other floor finish is as easy to confirm..  (or remove) 


 

woodguydan's picture

(post #112381, reply #14 of 63)

oh and Glitza was formulated in the 1930's


Edited 7/15/2009 1:44 pm ET by woodguydan

frenchy's picture

(post #112381, reply #16 of 63)

I know that it wasn't the normal finish used on flooring  untill well after WW2

cank's picture

(post #112381, reply #12 of 63)

It might be brown oak???
"is it strip flooring which was top nailed?" No I don't think so, it's 1.5" tongue and groove over 3/4 tongue and groove decking laid on a 45.

Marc

Omah's picture

(post #112381, reply #9 of 63)

drum sanders are really tricky, but there are floor sanders out there which have a series of random orbit sanders on the bottom of them. these are a little bit more foolproof to use than the old standby drums. that is if you've made a decision to sand through the poly.

DanCC's picture

(post #112381, reply #18 of 63)

I know what you are dealing with -- I have the same issues in my house.  You pull up the carpet and find the floors in pretty good shape, except for a stain or two and worn finish in high traffic areas.  What I did was spot sand where needed and apply a couple of coats of tung oil, followed by a couple of coats of shellac.   I found the tung oil (after cleaning the floor very well) blended better.  However, the tung oil will not provide any real protection, so you will have to cover it with something hard like shellac.  I did the downstairs hall and the stairs to the second floor about 5 years ago and it is holding up pretty well.  On the different colors in the wood, I had an area where there was clearly a color change in the wood caused by a carpet protecting part of the floor from sun.  The sun exposed area was darker-- after about 6 years, the line has gone away as sun light has gotten to the area that was protected before.  Good luck.

Dan Carroll

DanC

cank's picture

(post #112381, reply #20 of 63)

Dan, I wish I would have read your post earlier. I have just finished putting on 4 coats of thinned shellac. The spots are starting to blend but are still visible. I made the mistake of going across the grain the first coat and ended up with overlap lines that are also starting to blend after the 4th coat. I thinned the first coat 1.5-1 shellac which may have not been enough. I thinned the rest 2-1 and that seemed to "flow" better. I am using a lambs wool applicator on a pole and each coat goes on fast.
I am letting these coats dry overnight and plan on doing several more coats tomorrow.

Here are a couple questions:
How long do I have before I need to use Shellac after I thin it?
When I clean the lambs wool applicator can I save that Denatured Alcohol to thin the next batch?
How can you tell when shellac is no longer useful? I bought some gallons of Zinzer amber that are 2 yrs and 3 mo old because those were the only two gallons left in the city.

Thanks,
Marc

Oh, by the way, the floor is looking beautiful.

Gretchen's picture

(post #112381, reply #21 of 63)

I think you are making a mess.  Just my opinion. I think you have no idea whether it is shellac or not. It seems you are just finishing over the "problems". You need to sand the floors and start over.


Oh, and don't spill any water on your shellac floors, and be careful of whatever you use to "wash" them.


Gretchen


Edited 7/15/2009 9:00 pm ET by Gretchen

Gretchen

frenchy's picture

(post #112381, reply #24 of 63)

Gretchen


 He does know it's shellac. The test is simple, if the finish melts with shellac it is shellac..


  Second don't be so quick to fear water..  I had an airconditioner flood onto the floor which was shellacked about a month earlier. Giant puddle that had been there for many hours.  I grabbed a towel and wiped it all up then fixed the A/C to stop the flooding.  (I did this all by feel in the dark{I hadn't gotten lights hooked up in the billiard room yet}#  In the morning  I went up there expecting to find the floor all white..


 OOPS!!!!!


  The only indication of flooding was that area was dust free!  I would estimate it had been wet at least 6 hours.


 I know eventually shellac will turn white under water. I set a can down on one of my timbers and the sweat that ran off it caused a ring to form the next day. About a minute later I had the white off and first repair coat on.. Every time I dragged out the shellac I get another coat on and now you cannot find where I goofed..  If I could have stood the waiting. 15 minutes first coat, 30 minutes second coat, 1 hour third coat) with about 30 seconds to swipe some shellac across it for each coat I could have repaired it in  1 hour 46 minutes..  simply standing around for 1 hour and 45 minutes waiting for it to dry isn't my style though. 


DanCC's picture

(post #112381, reply #22 of 63)

I would be concerned about shellac that old, but if sealed, you may be okay.  Once thinned, you don't have much time with the mixture.  I did not use amber shellac because I was using the tung oil to get the color right, and just wanted the hardness from the shellac.  Water is not a real problem with shellac, don't let water sit for long periods, and make sure the surface is dry before you apply.  Alcohol is a anothers matter -- it will dissolve shellac.   If is has been more than a couple of hours and you don't have any surface problem showing, you are likely all right.  The finishes you are likely to have in a 50 year old house are going to be oil based if there is a problem it will show up pretty quick.   I don't pretend to be chemist and understand all the different types of finishes, so I usually make a point of testing in an out of the way area first.   Don't let you have to sand and start over crowd get too you.   If you floors are like mine, 90 percent of the area has a good finish that the carpet protected -- it is the high traffic areas and a few spots you have to worry about.  You can spend a great deal of time working on matching those areas and still be time, work and money ahead.


Dan Carroll

DanC

Gretchen's picture

(post #112381, reply #25 of 63)

The other possibility (I have read through the posts, and added some ideas) is to lightly sand the floor and refinish with poly. It just might even out all your problems of matching stain, evening out the spots you have cleaned up, etc. You could even tint the poly to match.  And floors are the ONLY place I have any use for poly, I would add.


Gretchen

Gretchen

DanCC's picture

(post #112381, reply #26 of 63)

That would work certainly.  I was under the impression that the idea was to avoid sanding the whole floor, even lightly.  Given the dust and disruption and the noise I got SWMBO, I think the whole floor sanding option must be a last resort.

Dan Carroll

DanC

Gretchen's picture

(post #112381, reply #28 of 63)

But this would not be a huge sanding operation. It would need to be cleaned and even sanded with a pole sander.  Wouldn't be a difficult clean up or a lot of dust.


And Frenchy, give it a rest. You are going on ignore because you are a one note and a complete bore. I have NOTHING against shellac--but there are other finishes in the world.



I am trying to help someone by offering a different possibility. He can make up his own mind.


Gretchen


Edited 7/16/2009 11:59 am ET by Gretchen

Gretchen

cank's picture

(post #112381, reply #29 of 63)

Gretchen,
I didn't think it was OK to use poly over shellac because of the wax?
Poly might be an option mainly because of availability. I am wondering about the soundness of the coats I put on yesterday, as they still leave marks when I walk on them. The Shellac was man. on 2/18/08.
I have managed to blend the spots however, by dabbing on shellac with a brush to each spot, letting it sit 15 sec or so, and then feathering it out.

Gretchen's picture

(post #112381, reply #30 of 63)

Sanding will help with the adherence.

Gretchen

Gretchen

cank's picture

(post #112381, reply #31 of 63)

I think I might end up going with poly because after 36 hours I can still leave a handprint or footprint in the shellac and it feels "soft".
It's too bad because I love the rich color.
The room I have done is only 10x12 and I still need to do about 750 sq ft in the rest of the house.
What is the best way to remove the shellac? Flood the floor with Denatured Alcohol and scrape it up with a floor scraper?
Or, will this floor eventually harden-up to where I can just leave it.
You mentioned tinting poly, is that something I would have to do or do some of the box stores do this?

Thanks,
Marc

frenchy's picture

(post #112381, reply #32 of 63)

I'm guessing because I've never had a problem with soft shellac.  But eventually the alcohol which is what is keeping it soft will work it's way out.


  If you do decide to remove it it comes up with denatured alcohol and no you don't have to scrape.. simply get it wet and then wipe it up..


 I stripped a 80 year old piano that way and it took me about 8 hours.. it would have taken me less time except I wanted to save the original decals so I protected the underside of the lid.