what is MDO, where is Mr. Trupan, & who's got the best vacs?

[God's Girl]

copied this from my reply to a different thread in the ShopBuddy....

Hi, Hi,
Sometimes life is like one long thunderstorm; but, I'm back in a speed boat and headed for finishing my woodshop! Yahoo! Thank You, God! So, we're at the point of designing the table/vacuum hold-down. Hence, I'm gleaning every table and vac system thread I can. There is no way my shop will ever by "dehumidified," and I don't want to be redoing my base board because of something out of my control. My questions:
1) Has anyone tried a metal sheet as the "rigid" structure? Just too $$?
2) What about some kind of rigid, solid plastic (seem to remember seeing something about that)? Again, just too expensive??
3) Am I being too blonde here...what is MDO vs MDF?
4) OK, I give up, what is Medex? (someone who used to be in med icine ha,ha)
5) Anybody got Mr. Trupan's address? Can't seem to find him anywhere!
6) Can you suggest a vac better than Ward's Lighthouse Central Vacs?
Oh, speaking of Ward...If you don't stand on your convictions in EVERY aspect of your life; well then, they aren't really convictions now are they! Go Ward! If someone doesn't want to do business with him, you reeaally don't want to do business with me! Can you see my tears? :D I plan on carving scripture into every single thing I make! Givin' God the Glory!
7) Do i really need 2" PVC for my vac hold-down? That seems like a bit over kill...
8) Did anybody get REAL assembly instructions?
__________________

[knight_toolworks]

You do know Mr ward believes you should only be home doing housework and raising babies? not running a shopbot.
Please no more sermons.

[michael_schwartz]

MDO is generally an exterior grade plywood with a medium density overlay. It is useful when you want the strength, screw holding ability, and moisture resistance of plywood, but with a smooth face that takes paint well. It also gets used for concrete forms.

MDF stands for medium density fiberboard, aka particle board that has been made from wood that has been ground up into a fine powder, mixed with glue, and pressed into a sheet. Don't let it get wet, or expect it to hold a screw very well.

I have two small 30 pint dehumidifiers and they do a nice job drying out my shop which is about 1000 square feet. They are especially important if you have a concrete slab. I have an inexpensive hygrometer/thermometer from Walmart which was about $10.00 or $20.00, and it records high/low temperatures along with humidity.

Conditions greater than 55% humidity are not only a health risk as they harbor mold/mildew, but they are unsuitable for for working with wood products. Cast iron machine tops are likely to rust. I consider 50% to be of concern and I try to dehumidify my shop to about 40-45% in the summer. Consistent humidity is important as wood moves and parts you cut may not be the same another day if the conditions change. Conditions greater than 55% or lower than 25% will result in excessive wood movement.

I do not use a vacuum hold down so I generally wait until my spoil board is trashed before I resurface. I find that I do however need to re surface seasonally. All of a sudden you will notice a problem with the Z depth being out of whack in some spots but not others. Maintaining consistent humidity and sealing the spoil board will help with this.

[waterwheelman]

Let Mr Ward speak for himself.
Go God's Girl.

[harold_weber]

To find the closest supplier for Trupan, I sent an Email to:
<rsimonsen{at}tumac.com>
He gave me a supplier in Indianapolis and one just south of Cincinnatti. This was in the spring of 2010. He might have one closer to you. Trupan comes in several densities. You want the "Ultralite" version for a vacuum spoilboard.

For Medex, just Google the word.

Yes, you really want 2" PVC. You want the lowest possible pressure drop in the piping, and 2" PVC will help.

[God's Girl]

Ruffle, ruffle. I always like to know where people fly.
Thank you Mr. Weber. I will definitely use that email. The 2" explanation makes complete sense, duh on my part. I just popped that Medex in there b/c it was time to get off the computer. I'll look it up.
Thank you, Mr. Schwartz. Although I'm familiar with MDF and the havoc humidity plays with wood and iron, I'ld just never heard of MDO before. We transferred all my woodshop equipment from sw TX to sw KY. I almost cried when we took it out of storage here to put in the shop. But with a large garage door on one end it is going to be a race to bring wood in and get that door closed w/o all that moisture coming in. i think i'll pick up an hygrometer this week and figure out where we stand. Where do you have your dehumidifiers placed? By your doors or in the middle on either side?

[bleeth]

Michael:
I am pleased to report that in my shop in Ft. Lauderdale we have humidity levels at or below 55%........................................at least one or two days a year!:D

[michael_schwartz]

Michael:
I am pleased to report that in my shop in Ft. Lauderdale we have humidity levels at or below 55%........................................at least one or two days a year!:D

Up here we get to see the other extreme when we struggle to get above 30-35 % RH when the heat is cranked up. The 25%-55% figure I cite is based on the average for most of the country with exception to tropical, or desert climates. I suppose in a tropical climate where the EMC for interior woodwork is closer to 11% MC 60% RH for example wouldn't cause the same problems as it would here.