Replies

1. 
   jackplane | Jun 10, 2004 09:07pm | #1

   spruce,pine and fir all fall into the same category of lumber for mostly framing material in home construction, with doug fir being strongest. If you frame your platform similar to standard framing with 2x4s or 2x6s, you should be fine.

2. 
   JohnWW | Jun 10, 2004 10:14pm | #2

   Brixton,

   You have offered way too little information for anyone to give you a reasoned opinion about your application, the load bearing numbers you found are irrelevant taken out of context.  Unless you are dealing with massive loads, a wood platform should serve your purpose, but its strength will depend far more on its design and the quality of construction than simply on the choice of wood. 

   Pressure treated wood contains arsenic, but ordinary plywoods are fairly benign, though not chemical free, and even "pure" natural woods contain a large assortment chemicals, a number of them quite toxic.  The resins in softwoods are a commercial source of several fairly potent volatile compounds, such as turpentine, and for this reason pines and some other softwoods shouldn't be used to create boxes to store sensitive materials like photographs or valuable art. 

   Also, are you sure the wood you are thinking of using is spruce, if you are buying construction lumber it could be any one of several species of softwood.

   John W.

3. 
   jonsherryl | Jun 11, 2004 03:37am | #3

   As JohnW points out, you really have to get into the numbers here ( thickness of the wood and the spans of the shelves) to develop a quantitative answer...But if it's any comfort, spruce was the wood of choice among French Voyageurs for making canoe paddles, because of it's great strength-to-weight ratio. For the same reason, Howard Hughes also used it (at least for many strategic components) when building the Spruce Goose in the 1940s; the largest airplane of its time...Of course, spruce is not as strong as woods that are significantly denser, such as the oaks, but for it's weight it is a pretty sturdy and resilient timber.

   JohnW's other comment also deserves some consideration; "are you really sure it's spruce?" If you're buying it as S-P-F construction lumber, it coud be spruce, pine, or true fir. Most of the pines cut for this grade are denser than spruce, so their strength properties would be at least comparable to spruce, but the true firs in this mixed grade tend to be soft and also a little brittle. (Douglas-fir and the true firs are not the same) 

   As for dangerous volatiles, both spruce and pine contain substantial quantities of terpenes, so they aren't chemically free with respect to giving off fumes that could function as solvents to any petroleum distillate based materials in your sensitive equipment...Plywood would compound this problem in that it also contains volatile solvents in its adhesives...But I think this potential risk is manageable for either solid stock or plywood, if the shelves are thoroughly sealed with a finish that traps these volatiles...AND you make sure the finish is thoroughly cured before you load the shelves with equipment. 

   
   

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   Edited 6/10/2004 8:42 pm ET by Jon Arno

   
   

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   Edited 6/10/2004 9:57 pm ET by Jon Arno

4. 
   PlaneWood | Jun 11, 2004 09:50pm | #4

   Weld up a steel frame and layer it with aluminum plate!

   PlaneWood by Mike_in_Katy (maker of fine sawdust!)
   PlaneWood

1. 
   jonsherryl | Jun 12, 2004 04:39am | #5

   >>'Weld up a steel frame and layer it with aluminum plate!"<<

   Hey Mike, would you recommend a Shaker style...or something more along the lines of Chippendale? 

1. 
   PlaneWood | Jun 12, 2004 06:07am | #6

   Shaker style would look best for a lab.

   PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood

2. 
   dondownunder | Jun 12, 2004 06:47am | #7

   Jon

   I'm with Mike - also steel cabriole legs would be a tad harder to do than shaker inspired rolled hollow section :-)

   Don

5. 
   301 | Jun 12, 2004 07:35am | #8

   Use poplar.  It is a good strong knot-free wood that is stable enough for a work platform.  Poplar is always the "do-all" wood in my shop for all sorts of work-a-day projects.  It is commonly used as a secondary wood for nicer pieces of furniture.  You should be able to buy kiln dried poplar in Home Depot and maybe Lowe's.