Replies

1. 
   mike4244 | Oct 15, 2004 10:10pm | #1

   There are several good choices for exterior wooden columns. MDO (medium density overlay) is a manmade panel, similar to mdf but for exterior use. Also , depending on your locale, redwood, cedar, cyprus etc are rot resistant woods. Fir and pine have been used with good success if the paint is maintained.

   mike

1. 
   Napie | Oct 15, 2004 10:57pm | #2

   MDO is actually exterior fir plywood with a water proof paper overlay.  Its primary use is road signage.  It works great for exterior panel use, my porch columns are built from it with redwood trim and it holds paint very well.  I’m not aware of an exterior grade MDF.

1. 
   mike4244 | Oct 17, 2004 04:58pm | #7

   Your correct, mdo is plywood with an overlay. I suppose the medium density  part of the abrreviation  threw me a curve. Very good product for exterior plywood uses. I buy it primed for about $45.00 for 1/2" thick sheets.

   mike

2. 
   DougU | Oct 18, 2004 06:39am | #10

   Napie

    I’m not aware of an exterior grade MDF

   There is such a creature, I think it goes by the name of medex or something like that.

   You can find it at good supply houses. Its a bit pricey but it does hold up to moisture.

   I've used it on cabinets that were going to be out in boat or pool houses.

   Doug

1. 
   notDusty | Oct 18, 2004 10:44pm | #13

                     Hi Doug@es ,

             You are correct on the Medex , it was mfg , here in So. Oregon by the Medford Corp . "Medco" . Locally it was used for Whitewater raft frame floors . I was told it was pretty tough stuff .

                                           dusty

2. 
   Manchild | Oct 15, 2004 11:12pm | #3

   Are you going to build it with ventilation in the columns? I've heard that that is the best way to build them. Not sure why.

1. 
   kbb468 | Oct 17, 2004 05:11am | #5

   I have never heard of ventilating columns. I can't think of why you would do that either. I think I will use MDO although I haven't seen any at the few suppliers I visit here in the Detroit metro area. Dose anyone know where to get MDO from in this area? Thanks for the replies.

   Edited 10/16/2004 10:14 pm ET by kbb468

1. 
   Curtis | Oct 18, 2004 01:39am | #9

   Hi

   I am from Royal oak Mi.

   Im not sure what part of detroit you are from but Detroit plywood, is a great place to start looking for MDO.

   Plywood Detroit, Inc.13250 Stephens DriveWarren, Michigan 48089(586) 755-4100Fax: (586) 755-9598

   C.A.G.

   Edited 10/17/2004 6:40 pm ET by curtis

2. 
   Napie | Oct 18, 2004 08:15pm | #12

   Try Pontiac Plywood, corner of Walton and Baldwin, a couple miles south of Great Lakes Crossing mall.  Small family owned operation, great service and very fair prices.

3. 
   jako17 | Oct 17, 2004 03:43am | #4

   For paint grade coloumns I would definatly go with MDO .I tend to use biscuits and epoxy for glue up .Ensure that you put in button vents protected with insect screen top and bottom to remove the condensation,regardless of you choice of material.It helps to paint the inside as well .

1. 
   kbb468 | Oct 17, 2004 05:21am | #6

   Thanks jako, now the ventilation process makes since to me and sounds like a good idea. Thanks

1. 
   Curtis | Oct 18, 2004 11:58am | #11

   Hello again

   one more small note.

   I dont like biskets (not for turning) I would use a 12 sided bird mouth router bit to make you staves, and then glue and turn round.

   check it out. http://www.magnate.net/products/rout_bit/bird%20mouth.htmC.A.G.

4. 
   RickL | Oct 17, 2004 05:25pm | #8

   Did you try asking the question in the Fine Home Building forum? That's their area of expertise.

5. 
   jako17 | Oct 21, 2004 05:55am | #14

   Am I right in assuming that the columns are going to be square in cross section? If so MDO is the way to go .MDF does not have the stuctural strength as it is completely fiberboard.MDO however is very strong indeed especially in compression.DO NOT use MDF for structural work or your porch may become your hat

1. 
   PatMcG | Oct 22, 2004 10:24am | #15

   Are the columns structural? Or ornamental?

   If structural, is the MDO appropriate?

   Compare wood to MDO prices. White oak and cypress are both pretty reasonable around here.

   If you finish both sides of the material, you may not need the vents.