Revealing Scratches Before Staining?

[James White]

I am ready to start staining my oak floor. However when I did the second floor. After applying stain it revealed scratches here and there. That could not be seen prior to staining. I have tried using mineral spirits. But it does not seem to show that scratches like I hoped it would. Is there any other way of doing this?

James

[glenn bradley]

I use a 500 watt halogen work light (HF for about $10) and shine it across the surface. Wipe with mineral spirits and any unwanted scratches will be revealed.

[Lucas Bittick]

Hello James,

The stain shows the scratches because it soaks into the opened grain of the scratch at a faster rate.

Some more info would be helpful-- I have a bunch of questions:

How deep/intense are the scratches? What kind of scratches are they-- are they from the final sanding, are they damage, are they leftovers from the initial sanding?

What grade of paper did you sand with for the first run? If it was not course enough to level out initial irregularities, subsequent finer sanding will not remove them. Many people are not aggressive enough with the initial sanding because they underestimate the toughness of an oak floor. I wasted a lot of time using 60 grit sandpaper in my bedroom, and actually had to go back and use 24 grit in an initial sanding.

What was your final sanding grade, and what did equipment did you sand with? How have you been cleaning the floor between steps? What kind of footwear are you using on the prepped surface?

If your scratches are really intense/deep, this would indicate they are leftover from the installation or first sanding run. If they are not soo deep and have a uniformity, they are part of the deal unless you want to do another sanding run with a higher grit.

Having finished 2500 sq. ft. of oak flooring in the past year, I can tell you confidently not to be too particular. Many folks get into "fine furniture" mentality, forgetting that it is a floor. I can't find most of the "mistakes" that I was initially horrified about.

I assume you will use a polyurethane top coat. This has an amber tint and could very well mute the contrast between the scratches and and the rest of the surface. The topcoat is where the fineness of the floor finish will come into play. Careful screen sandings between coats will give you a beautiful, even surface.

[James White]

Hi Glenn,

This is what I have been doing. Were you staining? It seems that scratches you can't even see, magically appear. I'm not trying to say I have scratches all over the place. It is just a pain in the butt to sand spots once the stain is applied. The paper just loads rite up. Mean while I have to hurry up because I have areas that are starting to dry. I would just like to ease some of the panic factor. If you know what I mean. These are big open areas that uneven uptake really shows.

James

[James White]

Hello James,

The stain shows the scratches because it soaks into the opened grain of the scratch at a faster rate.

Some more info would be helpful-- I have a bunch of questions:

How deep/intense are the scratches? What kind of scratches are they-- are they from the final sanding, are they damage, are they leftovers from the initial sanding?

What grade of paper did you sand with for the first run? If it was not course enough to level out initial irregularities, subsequent finer sanding will not remove them. Many people are not aggressive enough with the initial sanding because they underestimate the toughness of an oak floor. I wasted a lot of time using 60 grit sandpaper in my bedroom, and actually had to go back and use 24 grit in an initial sanding.

What was your final sanding grade, and what did equipment did you sand with? How have you been cleaning the floor between steps? What kind of footwear are you using on the prepped surface?

If your scratches are really intense/deep, this would indicate they are leftover from the installation or first sanding run. If they are not soo deep and have a uniformity, they are part of the deal unless you want to do another sanding run with a higher grit.

Having finished 2500 sq. ft. of oak flooring in the past year, I can tell you confidently not to be too particular. Many folks get into "fine furniture" mentality, forgetting that it is a floor. I can't find most of the "mistakes" that I was initially horrified about.

I assume you will use a polyurethane top coat. This has an amber tint and could very well mute the contrast between the scratches and and the rest of the surface. The topcoat is where the fineness of the floor finish will come into play. Careful screen sandings between coats will give you a beautiful, even surface.

Hi Lucas,

You must have made this reply while I was typing a responding to Glenn's post. The scratches are very mild. Yes I am being too particular for most peoples taste. Its just my personality and I can't help it (I am kind of kidding here).

First drum sand with 36,60,80,100. Do all the edges with the with the edge sander. Despite what most people say about the drum sander being difficult.The edge sander machine is torture on your back. Oh man! I never want to use one again. Then just before staining I use a "square buff" machine with 100 grit paper. This is were I think the occasional scratch may be coming from. Despite vacuuming between every stage. I think this machine just likes to scratch floors.

James

[glenn bradley]

Hi Glenn,

This is what I have been doing. Were you staining? It seems that scratches you can't even see, magically appear. I'm not trying to say I have scratches all over the place. It is just a pain in the butt to sand spots once the stain is applied. The paper just loads rite up. Mean while I have to hurry up because I have areas that are starting to dry. I would just like to ease some of the panic factor. If you know what I mean. These are big open areas that uneven uptake really shows.

James

Right. The whole purpose of the exercise is to lower your blood pressure while staining. The mineral spirits should soak into and across the grain scratches just as the stain will. It is just much more subtle. This is why the high intensity cross-light and you've got to lean this way and that to get the right angle to catch a problem. A surface can look perfect until you move your viewpoint 90* and then suddenly . . . where'd that come from!

The type of stain will contribute of course. Minwax and Olympia oil base stains and their ilk are not finely ground. You can actually see the little grains of pigment in the finish. These will really show up defects.

Dyes are the most forgiving to me with gel stains running second choice. I reserve oils for non-pigmented use; BLO, Watco and such.

A regimented sanding protocol will minimize your problems. Same direction while working through the grits even if you think you don't need the "in between" grits. Vacuuming or tack cloth/brushing between grits. Most of my errors come from a stray piece of 220 grit that I accidently grind into the surface that I think is clean.

[James White]

Hi Glenn,

I am using duraseal. It is a professional stain. Tomorrows the big day. Or at least the first of the next couple days. Poly is up after the stain dries.

James

[Lucas Bittick]

James-- how did everything turn out? (and I agree, edge sanding is like trying to wrestle a wild animal).

[James White]

Lucas,

It went well. I only had about four spots that I had to sand during staining. I am pleased with the results. You can see some photos at the below thread.

http://www.sawmillcreek.org/showthread.php?t=90533

James