Thread: Need two pieces of hardwood, 1.75 x 6 x 43"

Ah... I think I might have it... the key is, you said 'standard practice'...

RAS

Yes, 'standard practice' part of it...but there is yet more...

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RAS, re nylon straps...you got some of the reasons right, but there is another more important reason to use a spreader bar.
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It spreads the load evenly, which in the case with lifting batteries, prevents a crushing action. If the cells where to be crushed, it would lead to short circuits, spilled acid, etc...

Mark

The best wood would actually be something like Elm. It is used for things like hubs for wooden wagon wheels. It resists splitting very well since it grows with a spiral that reverses itself year after year. It is also very hard. Harder than maple. Purpleheart would be another good wood. Another good wood that is exceedingly hard and tough is black locust. Elm is probably the most available,though. I know it wouldn't split through the bolt holes.

Nylon lifting/safety equipment and battery acid don't mix. If you want to use textile slings, they would need to be polyester for this application.

Nick.

D, I can have two 1.75 x 6 x 48" (You trim off the extra) on the way UPS to you tomorrow. Red oak or spanish cedar, your choice, thats all I have in 8/4 material right now. If you are interested we can work out price.

D. We make ours out of "Micolam". Lumber yard cuts to length and we just drill it. We stay with the 9 1/2" wide stuff, but you could rip it if you wanted to. Watch out for splinters until you get it coated with varnish or something.
JR

It spreads the load evenly, which in the case with lifting batteries, prevents a crushing action. If the cells where to be crushed, it would lead to short circuits, spilled acid, etc...

That's it, but you left out part. And that is, the lifting tabs themselves are prone to corrosion from battery acid and thus the side pressure imparted from a single point lift without a beam might tend to bend the lifting tabs. End result being pressure on cells at best and breaking the tab (and therein dropping the 4000 lb battery !) at worst.

Much less likelihood of bending or breaking the tabs by lifting "straight up" via a spreader beam.

The "standard practice" aspect is that many 24/7 operations have multiple batteries...sometimes fifty or more, and are changing out batteries with each work shift. With one of these, with hook positons set for their particular batteries, they can simply lower the beam unto the battery and it will hook itself if you do it right. So, it's simply faster than messing with seperate slings and such, as well.

jkilroy,Spanish cedar is a very soft wood.they used to make cigar boxes out of it. It is sort of in between mahogany and balsa in hardness. I do not think it would be a good choice. The red oak would be much the better choice. I have used Spanish cedar for decades. It is the traditional wood for classical guitar necks,being light and fairly stiff. I doubt that it would hold bolt holes from splitting very well,though. years ago,they used to also make the long collegiate racing hulls from Spanish cedar.

gw, re purple heart...nah, I think I'll use East Indian Rosewood, Cuban Mahogany, Birds Eye Maple or Carpathian Elm Burl, maybe with some inlaid marquetry of a nice nature scene.

Now, that's not exactly what I had in mind, but very close. I knew battery acid and nylon slings was not a good combination, but the tabs on the batteries didn't register. I figured they were a part of the battery case; molded in, not steel. Learn something new every day.
(And, Keith never did answer... )

RAS

Don,I was basing my choices on toughness,not fancy stuff. Besides,I don't like purpleheart anyway,except for toughness. It is very hard to work. I THINK they built the replacement ships for Jamestown out of purpleheart for durability and decay resistance. Personally,I think it is ugly. So is East Indian rosewood. If you want to get fancy,use the real stuff,Dalbergia Negra,Brazilian Rosewood.I have 1000 lbs of it. You can pay $900.00 for a blank guitar back of that. Actually,I would not recommend Brazilian. It can split. You need the ropey elm or purpleheart for maximum split resistance.

I know that nylon will react with acid.I would hope that you are not as careless as that .The wood beam may have to be stressed certified to carry the rated load.Seems to me that standard procedure here is you know everything about everything already,we have a word for guys like you up here in Canada,I'll let you know when you get it right, as if.

A common thickness for engineered lumber used for beams in the residential construction industry is 1 3/4". The widths vary from 9 1/2" to 24" for the common stuff. The reason for the 1 3/4" thickness is a 2 ply beam is 3 1/2" thick, the same as a 2x4 wall with no flitching required. Anyway, any lumberyard that deals with the homebuilders (generally not the big boxes) will probably have this stuff, and cutoffs/smaller pieces abound. A small piece like that would probably be free, if they have to cut it they would charge around $6.00/ft. Trade names are LVL and MicroLam, there are others. This stuff lookes like a beam made like plywood, thin wood layers glued up in layers under high heat and pressure. It would be perfect for your application, no grain to split at the bolt holes.

I happen to know this stuff because I design floor and roof trusses and sell a bunch of the LVL for beams.

My money would be on a buildup of hardwood marine plywood. Available, tough, cheap and not dependent on selection or drying technique for split resistance.
Mike

Another vote for LVL.

Seems to me that standard procedure here is you know everything about everything already,we have a word for guys like you up here in Canada,I'll let you know when you get it right, as if.

Ahhh...you made such a cute analogy...it's precious...utterly illogical, but precious.

But anyway, this is exactly why I don't like folks blurting out alternatives when I don't ask for alternatives. If I ignore them, it enourages yet more, and they always want to know "well, why not ?" so I'm obligated to waste time expaining "why not" and then their little feelings get all hurt-ee-o-poo....gawd... :rolleyes:

I had one of these with a pultruded fiberglas beam, had a steel one too. sold both to a forklift service guy.

Surplus, why didn't you offer them to me ?? (or was this in the spring of 1959 ??)

Personally,I think it is ugly. So is East Indian rosewood.

Now that you mention it, perhaps it is Brazilian rosewood that is the pretty one. I made a Chippendale mirror frame out of B. rosewood back in the mid 1980's. Got it from some old codger in Raleigh, NC who also had a cache of Cuban Mahogany from pre embargo days.




Perhaps a design similar to this would be chic ?