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Old 12-12-2007, 07:55 PM   #11
Sean McMaster
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Re: Platforms questions???

Same here, Paul. There's no way I can convince my wife to park the minivan on the driveway all winter, so any platform I get would need to be a speedbump too. Of course, I don't even have a barbell yet...
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Old 12-12-2007, 08:09 PM   #12
Scott Machalk
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Re: Platforms questions???

Just a point of interest here about stall mats. I was able to get a 5' x 8' stall mat at my local Farm & Feed store. Then I am planning on using a 3x8 sheet of plywood to give me more of a landing zone. Just wanted to let you know there are different size mats out there.

I am interested in this thread because I am getting ready to make my platform also. I really need to decide where it's going though because I don't want to have to move it.

I was thinking of just leaving mine with no finish. I suppose that would get dirty though, eh? I like the looks of the ones with the poly. I also like Tom's idea of using the Drying oil. Hmmmm... choices, choices.
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Old 12-12-2007, 09:48 PM   #13
John Swanson
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Re: Platforms questions???

At a farming store, I saw mats from 2x4 all the way up to 4x8 mats. There anything from $40 to $80 and come in 3/8, 1/2, 3/4. I know forsure that I want to use those on the sides but I know I want a finished wood look in the middle. I was also thinking about putting my family crest on the wood as a decal and then putting the clean finish over all of that...
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Old 12-13-2007, 07:10 AM   #14
Scott Dyck
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Re: Platforms questions???

I got ahold of some 3/4 treated plywood for free on Craigslist, so I'm going through the pain of building my platform soon. Pain because I have to put it outside (I have no garage, a gravel driveway, and a basement ceiling that is too low to lift overhead) and I have NO level ground, my whole backyard slopes all over. I have a brick patio, but it's kinda wavy.

Any suggestions? Do any of you guys have to keep yours outside?

Putting the platorm together is cake. The leveling part is gonna suck....I really don't want to have to put posts in the ground and build it up.....then I have to find a way to protect it from the elements....groan. On the upside, I got a sweet squat rack for $75 on Craigslist, and the dude drove 45 minutes to deliver it to me at no cost!

Sorry to jump into this thread, I just didn't want to post an extremely similar topic and get directed right back here.
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Old 12-13-2007, 09:10 AM   #15
Paul Findley
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Re: Platforms questions???

Regarding leveling: I built mine in my garage which slopes about 2" over 8 feet. It was fine to lift on but I got sick of rolling barbells. So I used overlapping thin layers of plywood on the underside to level it. If your going to build one, I suggest leveling it from day one, going back in was a pain.
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Old 12-13-2007, 10:15 AM   #16
Tom Fetter
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Re: Platforms questions???

Plywood, especially if left unpainted, uncovered and level, will delaminate when left out where the rain will get at it.

I'd be inclined to paint it with a high quality alkyd (oil based) opaque exterior stain, made for fences and decks. Put one coat on ALL the surfaces of the plywood, and at least 3 on the parts you'll stand/jump on. Staining all of the wood (rather than just the parts you see) will make the stain job much more durable .. if you don't, the unstained parts will take up humidity faster than the stained bits, and lead to premature surface failure.

The advantage of stain vs. paint is that it doesn't ever peel, isn't ever slick to stand on, and doesn't need scraping etc. before you re-coat when it looks dingy. A light colour will reflect away heat, which will help the job last that much longer again. An opaque stain (rather than translucent or transparent) has extra solids in it; the pigments help protect the wood more from UV, again making it last longer.

If you want to, you can do the sand-in-the-paint trick I mention on the thread about plyo-boxes, to make your surface non-stick. When the stain's wet, sprinkle on a heavy coat of dry sand. Once dry, sweep and vacuum off all the sand that didn't stick, then overcoat with 2 more finish coats. The sand won't stick as well to stain as to paint, but will be better than nothing.

Finally, were I making a lifting platform that I knew was going to be left outside in the elements, and had to use plywood, I might consider giving a bit of "crown" to the platform, rather than keeping it dead flat. You're gonna have to level this anyway, eh? Which means screwing the plywood down to some sleepers or beams?

Consider making the beams have a nice shallow arc, 1" or 1 1/2" higher in the middle than at the edges. That much crown in the structure won't affect your footing at all, but it will force the rain to run off. Will last much longer ...

t.
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Old 12-14-2007, 06:53 AM   #17
Scott Dyck
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Re: Platforms questions???

Good ideas, Tom. I agree about staining vs. painting.
Do you think 3/4" plywood will pull down to a crown though, without putting relief cuts on the back side?
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Old 12-14-2007, 09:09 AM   #18
Tom Fetter
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Re: Platforms questions???

Yeah Scott, probably 3/4" ply would crown that much without kerfing it on the back. I'd put a bead of construction adhesive on the beams though, so that the screws aren't the only thing holding it in place (one wouldn't want anything to suddenly go "sproing!").

I'd screw down the center of the panel first, and gently encourage the bend into the ply by putting in a line of screws 6" from the center on one side, then 6" from the center on the other ... and so on out to the end of the plywood sheet. Don't be tempted to use drywall screws - they're brittle! I'd use deck screws, as they've got a rust-resistant coating ... long enough screws to go about 1" into the underlying beams.

That said, if the panel does turn out to be too stiff to bend, most 3/4" I've seen has 5 plies. As you suggest, you could set your circular saw at a depth to cut through the first two, and kerf it from end to end every 4" or so on the back to add some more flex. Do it before you stain it, and slop lots of stain into each of those cuts before the thing's screwed into place, or you're inviting rot.

Since the platform will be laminated from two or more thicknesses of 3/4" plywood, that kerfing won't have any material effect on the strength of the finished platform so long as the glue bond between the sheets of plywood is substantial. I'd use lots of a premium polyurethane construction adhesive - it's as strong as epoxy and more flexible - so you won't shatter the glue line when you drop weights on the platform. Waterproof too. But hell to get off your hands ...

cheers!

t

Last edited by Tom Fetter : 12-14-2007 at 09:16 AM.
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Old 01-21-2008, 11:13 AM   #19
Christian Salas
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Re: Platforms questions???

Adding my recent wisdom building a platform:
1. I agree with Scott that you should try to build a narrower wood center strip and wider "Drop zones" with the rubber. Apparently this is quite controversial, but I made mine with about a 3'3" center and basically 2 1/2' rubber drop zones on either side. Of course that means you'll have to buy more rubber, but it will potentially be easier on your equipment and you don't have to "aim" it as much when dropping.

2. I used scrap oak hardwood flooring in the middle and love it. The only modification was I had to sand off the original "pre-finish" with 60 grit sander then further sand across the grain with a belt sander, digging into the wood with the sander at an angle. Then I applied 2 coats of water-based poly (no preference to oil, it was handy). I think the poly takes away the grip, but if it's roughly sanded the surface is perfect, as far as I can see.
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