I have a client who wants several out door furniture pieces made from KD after treated lumber. It is about 75% more expensive than the standard treated wood and that is their choice. My question is do any of you folks work with treated wood in your shop. For 30 years I have avoided using this wood in my shop due to not wanting to contaminate the shop with toxic dust. I suggested red wood, cypress, western red cedar , mahogany but because of the material cost he keeps going back to the trreated stuff. There will be about 60-65bd.ft material so the treated wood costs about $1.65per bd.ft. versus $3.50 for cypress and up even farther for the others. There wil be routing on all the edges, band saw work and plenty of ripping of stock. What is you input. Have any of you done extensive projects with this stuff.
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Replies
I have not, but just have to say, clean up well...
very well
Silence is golden, but ducktape is silver
Mr. Bird,
I recently needed some "quick and dirty" stands and platforms for the shop. I had a few 4 x 4 PTL posts out in the back left over from a deck project. This stuff was at least 7 years old and was not the new ACQ treated lumber. It jointed and planed OK but stunk to high heaven. RAS and TS blades immediately gummed up. I finished the pieces with 1723 coats of 1# cut shellac: it really soaked up the finish. The completed pieces look OK and serve their intended purpose.
However; working with the stuff was most unpleasant. Even with my obsessive-compulsive DC and clean shop habits the fine sticky dust got everywhere. The "pine-sol" smell is just plain odoriferous (and it stinks too.... <G>).
Bottom line for me is that PTL is great for building decks and fences but a PITA to machine in an enclosed shop setting. I would personally avoid working with it again in my shop.
Best!
-nazard
The "pine-sol" (turpentine) smell comes from the wood, not the fact that it's pressure treated. Southern yellow pine has a very strong fragrance when cut.
-Steve
Steve,
Gee, my old lady said it was something about "You de Cologne".....<G>
On a different and less acrid note, I am still "tuning" the dual DC setup although the switch from 5 to 6" duct is still yet to be done. Balance between the two units seems to be of some importance: one had a canister filter and the other a OEM bag. Replacing the bag with a canister was like tossing in an extra horsepower. Leaving a gate partially open at the end of the main run seems to help, also.
Before switching to 6" duct, I am going to experiment with a Phil Thien type separator or modify the DC units with Thien baffles. I'll keep you posted.
Best!
-Jerry
$$$$$
If they want to pay you to thoroughly clean your shop after, go for it.
Wear a mask, and clean every darn thing at the end.
$$$$$
I would work up an estimate that includes the extra time you will need to invest in cleaning your shop thoroughly, extra wear/tear on tools (if any), replacement of filters in your respirator, and see if using treated wood actually does reduce the overall price of the project.
There may be another factor to consider, that being any hardware and fasteners. I seem to remember something about this new treated wood needing special fasteners due to increased corrosion concerns.
One other wood suggestion if you haven't considered it: white oak.
White oak here in Ohio is a little over $3.00 plus more for 5/4 & 8/4. So it is in the high cost area as far as this client is concerned.
I did a couple of things with PT wood. I just took my tools (except t-saw) outside with an extension cord. Used the circular saw for anything that I would have cut on t-saw.
Why bother kiln-drying it if it's going to be outdoors anyway?
When you get right down to it, the chemicals used in ACQ pressure-treated wood are probably no more hazardous than many of the naturally-occurring extractives in some dense tropical woods. Nevertheless, I'd do as much of the work, especially work that creates a lot of dust and chips (like routing), outdoors as possible.
-Steve
The kd after treating is dry and not wet when worked and it is very stable, 2x4s are straight and flat. The wood is dried considerably less than regular TW but is not dried for indoor use. Also the quality is very good. For my deck I used 16' 2x4s and there was only one small knot on one side of 10 boards purchased. Laying the boards against each other there was no more than 1/8 " separation the entire length. I would like to see this done with regular TW. Again you pay about 75% more and it is difficult to find a lumber company that stocks it.
IIRC: You are going to have to treat all of the cuts, because the pressure treating doesn't penetrate fully into the wood, so you have to apply it to the cut edges. (Not sure on that, but think I read it in an article on the stuff in Fine Homebuilding.)
While the new stuff they are using is far less toxic than the old copper-arsenic treatment, it is still toxic, and you will need to devote time to cleaning up the shop and your tools.
So, by the time you add on to your estimate the cost of working with the PTL, and extra cleaning the shop will take afterwards, the cost differential will not be that much.
Do your customers understand that preassure treated wood in only treated on the outside, and once ripped, routed and cut, may not be as durable as they think? Just a possible leverage for you.
Brian
I've done a fair amount with it - building outdoor working tables and such for deck and yard. Some other posters have suggested that treated wood isn't durable once cut because the wood is treated only on the outside. That's false - the "pressure" in pressure-treated wood is there to thoroughly diffuse the organic chemicals and copper into the wood (the organics are a replacement for the previously used arsenic and is a fungus inhibitor - the copper is insect protection).
That's why treated 6X6" timbers are acceptable as structural supports in direct ground contact - it doesn't matter whether the end is cut or not.
However, I would suggest you refuse this job unless the customer is interested in a good deal of high-end interior work as well, in which case you accept the PTW furniture as way to get the rest of the job. When you think about it, $1.65 vs. $3.50/bf is insignificant for a few pieces of outdoor furniture - the time and tooling will be by far the majority of the job. And if the customer is so cheap that they insist on saving the $150 in materials costs, it might be best to not have them as a customer.
One particular observation about building with treated is that for any piece that requires reasonably tight and sturdy joints, you will have to surface and joint all 4 sides of any piece - it's just not straight enough to build furniture with right off of the truck. Doing so will take significant time (that I assume you will charge for), and will put significant wear on your tooling, not to mention gumming up your planer, jointer and tablesaw blades with resin.
"That's why treated 6X6" timbers are acceptable as structural supports in direct ground contact - it doesn't matter whether the end is cut or not."
From the AWPA FAQ:
--------8<--------
How should I treat cut surfaces of treated wood?
AWPA Standard M4 recommends treating any cut, bored, drilled or adzed surfaces of treated wood with a preservative solution. The most commonly available preservative meeting the requirements of Standard M4 is a Copper Naphthenate solution containing at least 2% copper. Allow the preservative to soak in before applying the next coat.
-------->8--------
-Steve
All of the literature I've seen for pressure treated lumber says that the cut ends must be treated to preserve the warranty. I have seen a fair number of PT posts where the chemicals quite obviously weren't as concentrated in the center as they were nearer the surface.John White
That isn't the reason for the recommendation that end-grain on PT lumber (or any lumber in an outdoor application) be treated. End grain, of course, allows significantly more water to penetrate than does face or edge grain, and water is the enemy of outdoor wooden items and will eventually cause its failure by expansion/contraction, whether it rots or not.
That said, the chemicals used to pressure-treat wood aren't just absorbed in the surface of the wood. Were that not the case, the national building code would require treatment of any cut surface of treated lumber, which it doesn't.
I just got off the phone with a rep from the Southern Yellow Pine Association. According to them applying a preservative to the end grain is to prevent rot, both because sometimes the preservative is not as concentrated in the wood at the core of a board and because the end grain tends to be more prone to rotting because it absorbs moisture more readily. He said the brush on preservatives that they recommend would not prevent end checking.John White
This is an excerpt from the American Wood Preserver's Association standard M4-02 - The AWPA is the standard-setting organization for wood treatment and is the ultimate authority in this matter, similar to the ASTM:
6.2 Lumber and timbers – Lumber and timbers with a nominal thickness of 150 mm(6 inches) or less which are used in above ground applications and are of a sapwood species such as southern, red or ponderosa pine, generally do not require field treatment to provide a good service life. When lumber is from a heartwood species such as hem-fir, larch or Douglas-fir, it should be field treated in accordance with Section 6.1.
The standard does recommend field-treating timbers that are subjected to aquatic environments or buried structural foundations, though the "field treatment" it's referring to is with creosote-like compounds, such as roofing tar. Doubt that would be appropriate for outdoor furniture, though it's true that such furniture (to me anyway) always looks and ages better with a wood penetrating sealer (such as the afore-mentioned Sikkens).
What you quoted doesn't address cut ends, the AWPA short answer, from their FAQ page is:"How should I treat cut surfaces of treated wood?AWPA Standard M4 recommends treating any cut, bored, drilled or adzed surfaces of treated wood with a preservative solution. The most commonly available preservative meeting the requirements of Standard M4 is a Copper Naphthenate solution containing at least 2% copper. Allow the preservative to soak in before applying the next coat."John W.
Actually, it does address cut ends. "Field treatment" from the meaning of section 6, applies to any surface that is milled or machined after the pressure treatment (i.e., "in the field"). The recommendation that you cite is the general case, and is addressed in section 6.1. Section 6.2 is the specific case where the wood is not more than 6" in cross section, and is not used in an aquatic environment or prolonged ground contact. In other words, a furniture application:
6.1 General — All cuts, holes and injuries such as abrasions or holes from removal of nails and spikes which may penetrate the treated zone shall be field treated. An AWPA accepted preservative system, determined appropriate in accordance with Section 7 of this Standard, shall be used for field treatment.
Field treatment preservatives shall be applied in accordance with the product label. The application method shall coat any surface that is exposed by damage or field fabrication while not using excess preservative. Any excess preservative not absorbed by the wood product shall be cleaned from the surface prior to the use of the product.
Bored holes for connectors or bolts may be treated by pumping coal-tar roofing cement meeting ASTM D5643 into holes using a grease gun or similar device. Careful attention should be given to materials placed into aquatic environments. These materials shall not be used unless the field treated surface is clean, dry and free of excess preservative.
6.2 Lumber and timbers — Lumber and timbers with a nominal thickness of 150 mm (6 inches) or less which are used in above ground applications and are of a sapwood species such as southern, red or ponderosa pine, generally do not require field treatment to provide a good service life. However, material with narrow sapwood faces or having heavy heartwood in cross section should be field treated in accordance with Section 6.1 when cut or drilled. When lumber is from a heartwood species such as hem-fir, larch or Douglasfir, it should be field treated in accordance with Section 6.1.
You might wanna post this over at Breaktime -- the guys over there use PT all the time & may have better insight. Not many of us Knots "furniture makers" would want our highboys left out in the rain! ;-)
You also might want to see if you can get ipe in the sizes you'd need to make this outdoor furniture. It's as weather resistant as the PT is -- at least for applications not in ground contact, like posts. It will also weather to look much like weathered PT (or any other wood left outside for a year or two), a silver-gray, except, IME, it checks and splinters less. It's also HEAVY. It won't be any easier on your tools, though -- probably worse -- and it makes a truly nasty dust when cut or milled. Don't know if it'll actually hurt you, but it's foul enough that you'll not want to work it unless you wear a respirator. It's THE go-to wood for decks these days when folks want real wood instead of one of the plastic wood materials.
As for FG's comment about fasteners, using ACQ pretty much mandates that you will need to use stainless steel fasteners, tho' brass might work also. When wet, the PT will leach CU compounds that set up an electrolytic reaction with any steel it contacts -- like acid rain on steroids. Normal steel fasteners will disolve to rust in a year.
If your clients have in mind "rustic" porch furniture -- as in 2X4s bolted together, picnic tables, and generally what I envision when I think of redwood patio furniture -- using PT will be no big deal. Indoor furniture techniques rarely work for patio furniture that will be left out in the rain/sun/snow. Think construction-type joinery methods rather than traditional furniture joinery. You should be able to build this type of furniture with only a chop saw and a drill. And maybe a circular saw for occasional ripping. Anything like paneled doors, mitered joints, edge-joined panels, etc., will quickly be checked, warped and twisted by the elements no matter what wood you use. Outdoor furniture is also notorious for developing splinters as it ages, so plan for that as well. It should hold up as well as, well, a deck -- which is what this stuff was designed for.
Mike Hennessy
Pittsburgh, PA
PS: As far as it's effects on your tools, it's not bad. I regularly cut the stuff with no ill effects on blades. (Never tried to plane it, tho'.) The only problem is if you get some that's really wet -- it's gummy as any wet pine would be -- but you shouldn't have that problem with KDAT lumber.
Edited 6/10/2008 8:14 am ET by MikeHennessy
As for FG's comment about fasteners, using ACQ pretty much mandates that you will need to use stainless steel fasteners, tho' brass might work also. When wet, the PT will leach CU compounds that set up an electrolytic reaction with any steel it contacts -- like acid rain on steroids. Normal steel fasteners will disolve to rust in a year.
This, by the way, IS in the National Building Code. "New" pressure treated load-bearing applications MUST use stainless fasteners, though there's a good deal of discussion about approving ceramic-coated fasteners for use with the organic-treated PTW. The older, arsenic/copper treated lumber is fine with galvanized nails/screws/bolts, if you have a stash available.
Hi Mike, Actually the furniture consisted of 3 adirondeck chairs, a 48" round table with a slat top, a couple of planters and a couple of foot rests and a couple of small snack tables. After hearing all the mostly negative comments I told the client PT wood was not a option. Told him there is an Amish shop about 80 miles away that makes only PT out door furniture and he should check them out. I doubt if I will get the job. But again I want to thank every one for their comments.
Actually, Adirondack chairs and slat-top tables are exactly the sort of design that would be OK to do with PT. They won't hold up forever but, hey, it's patio furniture, not antique reproductions. That said, the Amish shop probably can do it for a lot less than you can, and they'll blame the shop, not you, when the stuff doesn't meet their expectations in a couple of years. ;-)
Mike HennessyPittsburgh, AP
A wise decision, IMHO. Kudos.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
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