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Cleaning old barn beams

JB_Gibson's picture

We are putting 100 year-old red oak barn beams in a new home and we want to clean them. We are looking for a way to restore some of the "golden" color as opposed to the weathered grey. Is it possible to sandblast them without removing too much of the wood? Or is powerwashing our only cleaning method available? Any thoughts or suggestions would be greatly appreciated.

(post #162010, reply #1 of 19)

JB - How about using the cleaning solution that teak furniture companies sell to brighten up their teak furniture. If I remember right, Barlow Tyrie claims it restores the 'golden teak' look from weathered gray.

On the other hand, you could let them be what they are ...


(post #162010, reply #2 of 19)

I've done this a few times- sand blasting can be done, although it's somewhat more labor intensive, and the sand tends to drive into the checks in the timber, to fall out over the next 10 years or so. You tend to end up with more of a weathered, almost driftwood like texture. The best part about sandblasting is that it's a dry process.

I tend to prefer pressure washing. It seems to clean the wood without removing large quantities. I have a mid size Generac pressure washer (1750 psi) which works well.

The thing I've learned about working with old barn beams is that they often contain hidden beasties that you probably don't want in your house. Here in the upper mid-west, I don't think I've ever seen an old hardwood barn beam that didn't have powder post beatles in it. They leave little pin holes, out of which little piles of dust dribble. Over a very long period of time they can cause structural damage. There are a few ways to deal with these little fellas. One is to elevate the temperature of the beam to above 120 degrees F for 48 hours. This can be done on a hot summer day by devising an enclosure which will "greenhouse" up to the desired temp, and with a little supplimentary heat overnight (we use a kerosene torpedo heater). Another method is to gas the little buggers. One job I did turning an old barn into a house, we had disassembled the frame for moving, and stored it in a sea container (large air tight metal box used to ship goods via truck, cargo ship, and rail). We hired a pest control company certified in the use of methyl bromide to come and fumigate the entire container. Methyl is used to fumigate fruit in California for med flies, and while it's non-toxic to humans, it's a pretty nasty green house gas. There are other less harmful materials that can be used, such as Tim-Bor, which is a borate material that can be dissolved in to a solution to soak the timbers in, often with a makeshift canvas tub. I've not personally tried this, but I've heard it works well.

Good luck- the look of the old beams in your house will be fantastic and worth the effort!

(post #162010, reply #3 of 19)

You might true using oxalic acid. That is what is used in some "deck brightners".

(post #162010, reply #4 of 19)

How about the deck cleaners containing oxalic acid?

(post #162010, reply #5 of 19)

There's a process out that they use for cleaning the insides of burnt homes called Soda Blasting. Most companies doing this also offer corn blasting, far less damaging than sand!

(post #162010, reply #6 of 19)

JB, Chris's suggestion about using high heat is a good one and does work, altho' I've seen it used only for small amounts of wood that could be placed in a large-wide industrial oven, they were wooden planks later used for furniture building. When I lived/worked in Germany I encountered similar challenges w/post and beam construction and restoration, saw a lot of those wood boring-saw dust depositing critters. Often the wood decay was so great that we had to replace entire beams entirely or in sections, if let go those bugs will eat until the second coming. We had a rather toxic solution to paint on to disinfect large areas, had to use a chem suit, gloves, face mask and breathing apparatus for application, it would eventually evaporate with good ventilation. The name escapes me but I'll look it up for you, haven't seen it over here yet-haven't looked for it either tho'. After the solution dried out we used various wire brushes on a drill at a slow speed to get the desired look. Often, the solution was reapplied a second time. Eventually when all the solution was dried out and the beams cleaned, they were painted with a polyeurathane. A final note, if you do any sanding, planing, or cutting, ensure that you have removed all hardware from the beams-ie-nails, screws, and any iron. Good luck.

(post #162010, reply #7 of 19)

i The name escapes me but I'll look it up for you

Bill - This is probably what you are thinking of.


(post #162010, reply #8 of 19)

Methyl bromide is deadly to humans!!! When my wife inspects a site that has been fumigated she wears Self contained breathing aporatus(SCBA) when in area to prevent premature death.

California has been in the process of banning the chemical for years and will suceed soon because it is so deadly. Contact CAL-EPA for more information

(post #162010, reply #9 of 19)

While the need to get rid of the insects is valid, and the suggestions appreciated, WATCH OUT FOR CARPENTER ANTS (I rescue a lot of timber from old barns and houses) There wasn't much advise given on returning the oak to it's golden hue.
I haven't found pressure washing to be very effective, (no offense to anyone) and sand blasting will leave deposits and a rough surface.
There are two good options:
1: Very expensive, have them re-milled at a small saw mill, you don't have to take away very much wood to have a fresh beam.
2: Cheap, but labor intensive, Do it the old fashioned way with a scrub plane followed by a smoothing plane. (Or grab a hand held powered planer like DeWalt makes) Don't laugh, it doesn't take as long as you'd think. I just finished three 15' 12x12 oak beams that I pulled out of a collapsed barn. I'd say it took three hours per beam.
Take care and good luck.

(post #162010, reply #10 of 19)


Thanks for the reminder about carpenter ants. My experience is that they only seek out timber that is already hurting- that which is moist and/or already rotting. if you have ants in a beam it's cause for more concern than just the ants.

I too have tried the planer approach- and it does work. Most of the beams I come across are hand hewn, and planing them takes off this attractive texture. Until you hit a nail, when something else is often taken off..

re: bromide- I was told by the pest control folks that it wasn't harmful to humans, but was being banned as a green house gas. Interesting.. I wonder if I was being B.S.'d.

I have used deck brighteners (like Deckswood) with some satisfaction. Although I don't like the chemicals in them either..

(post #162010, reply #11 of 19)

If you chew up alot of blades,knives or chains from undetected metals in logs or recycled timbers this super scanner may be an option for you.

(post #162010, reply #12 of 19)

Don't make this project more complicated than it needs to be. I've dismantled old barns and sheds and reuse the beams all the time. First I remove any obvious nails, metal, etc. Next, I take a stiff brush and clean any loose material from all 4 sides. Then I use a combination of belt sander and random disk sander (both Porter Cable). I use the belt sander if the beams are relatively smooth and the disk sander if I want to preserve the hand cut marks. I use 60 or 80 grit paper for this operation. Next, I use my air compressor to blow away the dust, etc. Lastly, I apply an oil finish - it doesn't matter what brand or type you use - many times I just use boiled linseed oil. The trick is to cut it at least 50% and flood all 4 surfaces - a paint roller works well. Let it dry - that shouldn't take long - then apply another coat. Once dried, cut and fit the beam to the specific application and apply more oil cut with 10/15% solvent. The oil/solvent kills the powder post beetles, ants and anything else alive in the surface of the wood. I've been doing this for 20 years with great results - and most of the wood is red oak. The patina is wonderful - the sanding preserves it and the oil just brings it out and gives it a mellow look.

(post #162010, reply #13 of 19)

Did I forget to say go over the beams with a metal detector BEFORE you plane them? (must have been the bossa nova) I picked one up at a yard sale for 5 bucks and it hasn't let me down yet. Your right about carpenter ants only going after bad wood, but I tend to find plenty of bad wood connected to whatever it is I'm trying to get at. The worst part is wading into a collapsed barn and having a bunch of little contractors open a job site in your left pants leg! talk about working without a permit.
I use mineral spirits and a stiff brush to clean grey wood that I want to keep that way, but I've yet to find anything that will make a grey beam golden faster than me and my stanley, (and I don't even have to wear a rubber suit)

(post #162010, reply #14 of 19)

I did a quick search and couldn't find a definitive statement of what the toxic dose of methyl bromide is believed to be. There seems to be considerable debate about the levels. There does seem to be agreement that it is mutagenic, but again, the level of exposure is being debated. The following are excepts from:

Breathing methyl bromide can cause injury to the brain and nerves, lungs, and throat. High doses also can injure the kidneys and liver. Contact with the skin and eyes can lead to irritation and bums. After a single, small exposure with prompt recovery, no delayed or long-term effects are likely to occur. After a serious exposure that causes coma or convulsions, permanent brain or nerve damage may result.

Under The Montreal Protocol of 1991, methyl bromide was defined as a chemical that contributes to depletion of the Earth’s ozone layer. The definition was based on scientific data. Accordingly, the manufacture and importation of methyl bromide will be phased out in developed countries as follows: 25-percent reduction in 1999, 25-percent reduction in 2001, 20-percent reduction in 2003, and complete phase out in 2005. In developing countries, consumption will be frozen in 2002 at 1995-98 average levels, followed by 20-percent reduction in 2005 and complete phase out in 2015. Exemptions for developed and developing countries include quarantine, critical uses and certain preshipment uses.

There is no known single alternative fumigant, chemical, or other technology that can readily substitute for methyl bromide in efficacy, low cost, ease of use, wide availability, worker safety, and environmental safety below the ozone layer. Research by the U.S. Department of Agriculture (USDA) indicates that multiple alternative control measures will be required to replace the many essential uses of methyl bromide. For preplant uses, such measures include combinations of fungicides, herbicides, and insecticides; other fumigants; and nonchemical alternatives, including cultural changes in cropping systems, resistant crops, and biological control. For some quarantine and export applications, effective replacements include irradiation, heat, cold, and controlled atmosphere treatments.

(post #162010, reply #15 of 19)

We are putting 100 year-old red oak barn beams in a new home and we want to clean them. We are looking for a way to restore some of the "golden" color as opposed to the weathered grey. Is it possible to sandblast them without removing too much of the wood? Or is powerwashing our only cleaning method available? Any thoughts or suggestions would be greatly appreciated.

I realise this is an ancient (post #162010, reply #16 of 19)

I realise this is an ancient post but the quickest and easiest solution to this problem is dry ice blasting.

I do this in Nova Scotia although we do travel across Canada.The dry ice leaves nothing behind as it evaporates back into its gaseous state.The freezing cold temperatures will most likely kill any bug that is anywhere near the surface and the CO2 itself will probably take away enough of the oxygen from the little buggers  that they will be asphyxiated.The process does not remove much material and is usually only used for surface protective coatings such as waxy film etc. Will not remove well adhered paint so can clean painted surfaces of flaky particles for repainting. Great process all in all.



Restoring the color (post #162010, reply #17 of 19)

Oxalic acid is used to restore the color to weathered wood it can be purchased at fine hardware stores in crystal form and desolved on hot water or is available at boating stores under the brand name "Colorback", crystals are much cheaper