Exterior door mildew

user-171680 | Posted in General Discussion on June 25, 2006 07:53am

A couple of years ago I built a custom entry door for a new home in Gettysburg Pa. , out of hickory milled and dried off the property. The entry way is on the north side of the home and is completely covered by the front porch. There is a reoccuring mildew problem [dark grey] which is being wire brushed off and the door being reoiled seasonally. I used an outdoor oil purchased from “Rockler Woodworking”. which has been excellent for the other applications I have used it on. I have always liked the oil finishes as they are easy for my clients to maintain, rather than a urethane or varnish requiring sanding. Does anyone out there have any suggestions or experience, recommendations. Any advice would be most appreciated. Sincerely, Bill Atkins

Replies

SawdustSteve | Jun 25, 2006 08:26pm | #1
You have two basic problems: 1-door on North side of house and 2-door covered by front porch. Both of these situations will lead to mold growth. Remove as much of the mold as possible, then wash the door down with a chlorox solution or other moldicide to kill any remaining mold spoors. Do it a second time for good luck. Now apply your oil finish. Because of a severe lack of sunlight, this door will always be a (moldy) problem. Check around, there may be some oil type finishes with a built-in fungicide in them. Or.... tell your client that grey mold is the 'in' finish this year. SawdustSteve
HowardAcheson | Jun 25, 2006 09:14pm | #2
If the base of the oil finish is linseed oil, then it will provide a breeding ground for mildew and mold. You might want to try getting a "teak" oil at a marine supplier. Those products generally contain both UV inhibitors and mildewcides.

Howie.........
Dave45 | Jun 26, 2006 03:44pm | #3
Like Steve says, the northern exposure and porch are the keys to the problem. Can anything be done to increase air flow at the door (e.g. an outdoor ceiling fan)? You should also use a finish with an algaecide inhibitor.
Cedarslayer | Jun 26, 2006 10:06pm | #4
Teak oil is usually 20-30% BLO and 70-80% Kerosene. Turpentine Mixed with BLO might be a better solution. If I were trying to fix this, my guess would be to clean with Borax and Turpentine, And then use a kerosine garage heater to blow dry the door, hopefully with borax remaining soaked into the wood. Then I would treat with 2/3 BLO, 1/3 Turpentine. This formula is used a lot on log cabins in Canada so it might have the right stuff. As always, test on scrap before ruining something valuable.

I drill a hole in the end of my outdoor tools and fill it with BLO and Kerosine to preserve the wood. Apart from a few handles that this raised the grain on, this has been very effective. If the handle is on a tool that stays outdoors, I use turpentine instead of kerosene.

Tung oil is considered mildew resistant. It may be worth a try.

Edited 6/26/2006 3:20 pm ET by Cedarslayer