finishing rough sawn wood

[dug]

I have some rough sawn beams on my porch and also interior rafter ties that I'd like to put some oil on. I have heard here about a wood cleaner product but my local hardware supply doesn't carry it.

Any harm in going at them with a bucket of soapy water and a scrub brush?

[glenn kangiser]

I don't see it hurting them any.  We have a 91 year old washing machine made with a wood top and it is still in good shape.

Timberbrite is one product.  It is Oxalic acid - cleans and brightens wood.  Do-it stores have a similar product - they stock it here.

[MountainDon]

Cleaning it with water will raise the grain.   

[Redoverfarm]

Dug it would depend on what your choice of finish would be.  By this I mean to have the rough grain exposed or a light sanding to get rid of the "hairs" associated with rough sawn.  The Oxalic Acid will bleach some stained area out but will also bleach the surrounding also.  If they are extremely rough I would probably use a wire brush to remove the heavy material followed up with a rough grit 60-80 to knock down the high spots.  It is really a personal preference.  If you are going to follow-up by staining or finishing do so on a portion of the beam which wil be on top and out of eye's view.  Once you have profected the desired look then do the remaining portion and the other 3 sides.

[Pine Cone]

I just used a wire brush on the rough-sawn boards I used to cover my outhouse/shed.  That cleaned off most of the miscellaneous sawdust, dirt, and moldy surface crud.  From there is used a water-based stain, and it has held up well for the last three years.

I'd be nervous about using soap, not sure how paints and stains will react to that, even if you rinse it off.  You could always make up a very diluted bleach solution and paint or pressure-wash it on.  I did that to a moldy-rough-sawn house I bought back around 1988 and it cleaned it up pretty good.

[Jeff922]

I framed up our Victoria's during the "rainiest summer in recorded Maine history", and as a result, I had a lot of mildew on my hemlock beams.  The only thing I could do was apply straight bleach to kill it all.  It didn't seem to hurt them.

[MountainDon]

On the subject or mildew and mold....

Chlorine bleach does not kill mildew or mold, it bleaches it, removes the color and makes it appear to disappear.

There are products available that actually crushes and destroys the mold as well as acting to prevent future mold growth.

[Redoverfarm]

You are right Don. Most of the information discourages using bleach to kill mold.  Borate such was in the old cleaner "20 mule team" will work  well but I haven't seen it in years. If you can find some household cleaners with that chemical it should work. 

[dug]

Thanks for all the great ideas. I'll try wire brushing them and if that is unsatisfactory I'll look again for something like timberlite.

On the outside beams I was going to use a 50/50 blend of linseed oil and paint thinner. I know you have to re-apply that sort of thing every few years but the sun here seems to bake off whatever you put on anyway- unless some has a better recommendation.

[MountainDon]

John,

http://www.amazon.com/Dial-00368-76OZ-Mule-Borax/dp/B000RNBX0G/ref=sr_1_1?ie=UTF8&qid=1287189920&sr=8-1

[Pine Cone]

The Log Home Store sells all this sort of stuff...
http://www.loghomestore.com/nl-care.html

Satisfied customer, no other interest, but they are nice folks...

[rick91351]

Lehmans caries 20 Mules Team Borax if not available local.

http://www.lehmans.com/store/Home_Goods___Cleaning___20_Mule_Team_Borax___627977?Args=

[Don_P]

I'm sure borax has bug killing properties as well, just interjecting the little chemistry I know. The fungicide/insecticide form of boron is borate... Tim Bor, Boracare, etc. One way to make the borate you see in those products, disodium octoborate tetrahydrate, is to boil borax and boric acid together. Combined, the two make a borate.

If you want to go smoother than a wire brush but still keep the basic texture an osborn brush works well. It is a cup type brush with grit impregnated nylon bristles. I've used one to clean 165 years of soot and stains off the inside of an old log cabin, worked well.

[Jeff922]

You're right MtnDon, I researched it a little.  I always assumed bleach kills mold from my experience as a housepainter during college.  Apparently it does "damage" mildew but doesn't completely kill it.  I should be okay though, because I sanded the beams after the bleach treatment.  This is good info to be aware of.  Always learning...