Interior log wall cleaning

[Jennifer Johnson]

I posted a question a few months ago and we are just now getting into our home to clean up and finish the log walls on the interior. I reseached the chemical products for "bleaching" and cleaning the walls before sealing.Based on some replys I got and research We decided to go with just sanding to avoid possible damage to wood if not rinsed well enough. We today put the first coat of water based poly on and were very disappointed that the walls looked very blotchy. Not from the poly,but the sanding job we did. We used 60 grit discs to get the most yellow/dirt off. It looked like we had done a good job, but like I said, it was horrible. Before we go on to do the other rooms, does anyone have a cleaning agent the have used that is safe for the wood, but would lighten the wood and stains before we start sanding? We can't hose the upstairs walls to rinse since the second floor flooring is on, but I supose we could do the great room and downstairs that way if it was the best option. We have sanded the walls thoroughly again and will apply another coat of poly with hopefully a better result for the rooms we have already done. Any info would be great! We are going for a more natural/light look to the logs so did not apply a stain which may have helped hide some blotches! Help please! Thank you!

Jennifer

[Merry Anne Hensley]

Picutre #62 - This has one coat of poly, correct? If so - you could sand off the poly, treat those areas with an oxolic acid solution and probably be able to remove those. These look like iron tannate stains. If not, you could do the same hiding procedure I suggested for picture #53.

[Jennifer Johnson]

These were black stains before sanding. Does that fit with your iron tannate stain idea? If so, I may sand the poly off and try getting rid of them. If I use an oxolic acid solution-I have a product called X-180-it says to rinse thoroughly. Is sponging off enough?

[Merry Anne Hensley]

I'm not familiar enough with this product to advise you there. I would check with the manufacturer on that one.

[CharisB]

X-180 is Oxalic Acid. Please do NOT use it interior! It's very difficult to completely neutralize on the interior & will cause you more problems. It's takes lots of rinsing, sometimes followed by a baking soda paste to neutralize....yuck. Sponging is not enough...

[Merry Anne Hensley]

Picture #85 - It looks to me like this is a distance shot of the same area as #53. Correct me if I'm wrong. The cross support beam does have some iron tannate stains. I can see the strap marks. If it has not yet been coated with poly, you can use the oxolic acid solution to remove those stains. If coated, again, try and hide.

[Jennifer Johnson]

stairs pic

[Merry Anne Hensley]

The steps look to me like some of the wood was sanded smoother than the rest. That is where the blotchiness comes in. Where it is "yellow", the wood has accepted more of the poly. The lighter spots look to me like you had a little mill glaze on the surface, and it would not let the wood take the finish equally. I'm not 100% on the ins and outs of Sikkens finishes, so really can't state exactly. I do know that many of the poly's out there "yellow". That is just the nature of theproduct. Is Sikkens one of them? I can't say for sure, but it looks to me like that is what has happened. Applying another coat without getting an even color would only make it worse. Remember - clear finishes do not hide anything, and actually bring out all the inconsistencies in the wood.

[Jennifer Johnson]

The Sikkens product does not yellow (the water based anyway) We used it on some ceiling boards a while ago and got no yellowing. There were a few areas that were excessively yellow like it was a stain of some kind-not with the grain of the wood and I could not sand it out no matter how much I tried. Is there a fungus or something that causes that?

[Merry Anne Hensley]

There is not a fungus I know of that would cause yellowing. It may just be that there was something in the soil where those trees were growing that gave those logs more of a yellow color. You can try the log wash and see if it helps... my offer still stands.

[Jennifer Johnson]

Ok on to blotchy--the wall with the window hole to the left is the wall I orginally wrote about. We sanded with 60 grit and put a coat of poly on and this is what we got. The wall with window to the right and yellow closet wall next to it is the one we resanded 3 times and has two coats of poly on-it is getting one more coat and will be considered done. The yellow closet is not getting sanded, but I made sure it was i there so you could see what we are starting with.
The pic with only a few boards in it is what it looks like before any poly goes on. This one has been sanded with 60 and 120. Dad was considering going with 80 and 150 instead like Charis said, do you agree?
What does the Log wash do that the vaccuuming doesn't get?
Thanks SO much to both you and Charis for your time
Jen

[CharisB]

Hi, Jennifer. Thanks for the pics!

Go ahead and stick with the 60-120 combo you have going on right now. No need to change to an 80 grit that first time around.

As for the dark spots you have - if you did the bleach test and some comes off, some doesn't, you could have a combo of mold/mildew and tannin staining. Tannin staining is not much to worry about - it's not aesthetically pleasing, but doesn't affect the structure of the wood. Mold/mildew in & of itself isn't an issue, but is a precursor to other major issues....Kill that mold! Sodium percarbonate cleaners (oxygenated bleach) are pretty gentle when used in a mild solution and can be rinsed with rags. Use a very mild mixture - I'd say a 10% solution - and be sure to rinse it off. And test first!!! You will have to follow that up with sanding.

On the ceiling, don't bother with the 2nd sanding of 120 grit. 80 grit will leave it smooth enough for your purposes and won't be noticeable from down below. I would still encourage the use of a water-based sanding sealer. There are several on the market. OR, contact Sikkens to see if they have a specific brand they might recommend. That will help prevent some of this.

The yellowing very well may be just the natural tannins in the wood being highlited by the clear coat and may very likely happen with any other clear coat, as well. This is a normal thing. What kind of wood do you have?

Hope that helps some more. Wow - lots of interior finishing! It will look great once you have all your Christmas decorations hung.... :-)

-- Charis

[Jennifer Johnson]

Thank you,
You're right, Christmas will be GREAT! The wood is pine, very soft. I have an occilac acid product called X-180. It is advertised as a deck restorer. Should I try this on the mold?
It says to wash thoroughly though.