Uh, yeah, that kind of freaked me out....

[G._Hoffman]

Everybody who makes stuff has some kind of scrap left over.  Left over resistors or tubes from old amp projects, tubes and chains from my bike, extra hard drives or memory from computers, etc.  If you're resourceful, you'll find uses for some of it.  

Around our shop, the most common form of scrap are blocks of mahogany.  We buy big 12/4 or 16/4 boards for making necks, and there is always an odd length bit of scrap at the ends.  Plus, as careful as we are to make it otherwise, there is always a lot of scrap left over from the making of neck blanks.  And we find a lot of uses for this stuff.  Sometimes it gets used for structural repairs on guitars, a lot of it gets used as cauls or sanding blocks.  I made a bulletin board for a none profit I work with that used a bunch of it to very good effect (if I do say so myself!)  About a month ago, I found a piece that was supporting a screw post holding up one of the shops main beams.  This was a piece of wood about 2"X16"X24".  Just a bit too short for a neck, and so dad just threw it under when he moved the post.  It is, however, PERFECT for a one piece electric guitar body!

So, I wanted this piece of wood.  I cut a couple 2x6's to support the beam for a few minutes as I retrieved the piece of wood, and I grabbed another - smaller - piece of mahogany to act as a pad for the post.  I was getting everything set up, not planning of finishing it because I'm not exactly confident in my abilities at construction, but just getting everything ready so I could have dad check it tomorrow, and we could do it in just a minute or two.  Great, easy and all.

Then, as I was putting the 2x6's in place - just so they would be ready to go tomorrow - well, they were apparently a bit longer than needed, because all of a sudden the screw post fell over.  Much before I was ready for it.  So, OK, really quick, get the 2X6's plumb(ish), pull out the block I'm keeping, set up the screw post again.  Except I can't find the pin to hold the two telescoping sections together!  And those 2X6's are just being held by gravity, and the are resting on a very poor quality concrete floor!

Don't you know it, I finally found the pin (after about 10 minutes) right next to the pad they the post sits on.  The one place I DIDN'T look.  Typical.  I think it is all back together right now, but I'm leaving the 2X6's in place until someone more competent than I can look at it.

I got my wood, though!

The post (and the 2X6 temporary support):





My new guitar (eventually):





I'm still half convinced the building is going to fall down on my head while I'm sanding in there!


Gabriel

[G._Hoffman]

On the other hand, when you end up with this:





...it all seems a bit more enjoyable.  This is going to make a nice guitar!  Its got a little checking on one end, but that's to be expected, and there is plenty of clear length left. 


Gabriel

[stingray_65]

Funny isn't it,

What a Man will go thru and laugh about later just to get a little somthin of what he wants

Been thru worse to get less myself!

gorgeous slab there Gabriel. I'm sure it will be a fine guitar soon!

I'm curious, how long has it been under that support beam?

Ray

[G._Hoffman]

Funny isn't it,

What a Man will go thru and laugh about later just to get a little somthin of what he wants

Been thru worse to get less myself!

gorgeous slab there Gabriel. I'm sure it will be a fine guitar soon!

I'm curious, how long has it been under that support beam?

Ray

I would say at least ten years.  I think that post was probably put up when we got our thickness sander, so that is probably when it was put in place.  But we had probably already had it in the shop for a while by then, so it may have been in the shop for 20 years or more.  We have a habit of not throwing things away.


Gabriel

[Ritchie200]

Too cool!  That is the equivalent of finding the dusty mint 55 chevy in the barn, isn't it?!?!  Yes, that will be a beaut of a guitar, you must keep us updated with this project!  AND you have to come up with a cool name for this one!

About 13 years ago I found an 1.5" piece of clear lexan about 2ftx2ft that my company was throwing out.  I had dreams of Dan Armstrong dancing in my head, but then I figured I had to come up with a cooler design.  I'm still thinkin'.......

Jim

[rafe]

  Those metal posts are not as strong as you might think and should never be used where a lolly columb is needed ....which makes me tend to think that what is above it would sag not come crashing down on you
I've put in plenty of beams and got rid of the columbs all together...Their is always that moment of doubt when I expect calamity....Fortunately it hasnt happened...I replaced the main beam in a four story house in brooklyn.In the basement, I had to build a temporary wall a few feet back on each side of it and then remove the beam and columbs....There was a moment or two.... real old place too....brittle....make sure that the 2x6's are secured with nails ...heads out is ok for easy removal ....or screws....

[PRR]

> ...as I was putting the 2x6's in place - .... all of a sudden the screw post fell over.

A woodworker is not a carpenter. I wish you would ask someone who builds/breaks houses for a living.

The lolly-column SHOULD have been securely fixed at BOTH ends. Even more than crumpling, these things fail by getting knocked-out.

The low working load, and the high liability to knock-out, is why these things are generally NOT allowed as permanent support.

The two 2x6s... are they WELL spiked? If not, the slenderness of a 1.5"x96" strut exceeds 50, and begs to buckle. Unlike simple compression and tension in wood beams, buckling gives NO warning.

> very poor quality concrete floor!

How poor? The 3"x5.5" footprint can "punch through" around the perimeter. 17" of perimeter, say 100 pounds per linear inch of perimeter for "very poor" thin concrete over soft dirt, is less than a ton, less than 8'x8' of light storage above.

I will say.... lolly column on concrete may be better than a fencepost IN concrete, like I had. At some point they cut through the MAIN beam to install a floor furnace. To discourage collapse they jammed a fencepost each side of the cut. The post stood on a rock on dirt. Later a concrete floor was poured. The rising damp ate the bottom of the post: it was loose and useless. No wonder all the doorframes upstairs were diamond-shape.

Some clear 2x10 pressure-treat. Cut 19" long. Lay two flat E-W. Liquid Nails. Two more planks N-S, crib-like. One more on top E-W. This has enuff perimeter to take several tons on cheese-crete, and is less likely to punch-through than hard steel.

Of course if the concrete is that cheesy, you really should hammer a hole through it into the dirt, drag in 200 pounds Quick-Mix and a couple large rocks, make a PROPER foundation.

You really should have one of these temporary for the lolly, and another permanent for the proper column. Lolly should have a screw. These things are fairly useless. You really want a house jack. And enuff 6x6 cribbing to raise it to the beam. Don't try to stack a post on a jack, it fails vigorously.

I replaced my rotted fence-post with a 6x8 "swamp oak" (turned out to be SYP PT, which is maybe better). This under a sub-beam which bridged the cut beam and overlapped many feet. I jacked until plaster cried, trimmed to a neat force-fit, and let jack down. Then I added bracing so it wasn't easy to knock-out.

There's other ways to do it. Much easier ways. However IF the beam above collapses, or even shifts significantly, your employees may get in the way as stored stock/scrap falls, and business will be disrupted for cleanup and repairs. Figure a couple guys a couple days sorting and fixing, instead of doing paying customer work, the cost of doing it right (by someone who knows right) becomes small.

And for modern "mahogany"?? Bah. The house above the rotted fencepost, the north wing had recycled hand-adzed (pre-sawmill) perfectly clear beams 4"x6" 13 feet long, and as near as we could tell it was 150+ year old old-growth walnut. We joked about ripping it out and up to pay our taxes.

[G._Hoffman]

> ...as I was putting the 2x6's in place - .... all of a sudden the screw post fell over.

A woodworker is not a carpenter. I wish you would ask someone who builds/breaks houses for a living.

Dad used to work as a carpenter (albeit about 40 years ago), and has OK'd everything.  Aside from the fact that he knows a bit about this stuff, and the fact it is his building, we're OK now.  I've also bolted everything together, nice and solid now.  No more worries.  The 2X6's were solidly screwed together while they were in place (they are out now).


Gabriel

[Bassmanster]

Should be able to look up a buckling safety computation somewhere for wood type, cross-section, load and length.  I had that in machine design but it was centuries ago.

[supro66]

Should be able to look up a buckling safety computation somewhere for wood type, cross-section, load and length.  I had that in machine design but it was centuries ago.

I WAS JUST LOOKING AT THIS SITE
http://www.hardwoodinfo.com/species_guide/index.php