Exterior Door

[Mike Walsh]

the front door on our house was replaced about 8 yrs ago with a Simpson glass over wood panel style in douglas fir. The door was stained and then finished with 4 coats of Minwax Spar varnish when installed. The entry is well protected from weather by a wide soffit, but gets a few hours of the late afternoon sun. The original finish held up well for about 5 yrs, at which time I had a painter look at it. He suggested sanding (not to bare wood) and re-coating with Waterlox Marine. From what I remember reading at the time, Waterlox Marine was ok over the Spar varnish so we went ahead with that plan. The Waterlox didn't hold up as well, and another coat applied less than 2 yrs ago seems to be doing even worse.

Any thoughts on whether the Waterlox is the right product to be using - and if not, suggestions on an alternative and associated prep work?

Thanks,
Mike

[Edward Dyas]

I wouldn't have used a tung oil product over spar varnish, especially an old finish. Tung oil needs to penetrate into the wood to be effective. The minwax spar urethane isn't one of the better finishes. You would have been better off with a marine grade spar varnish.

From where you are I would recommend chemically stripping the finish off the door, sand it and start over with a fresh spar varnish. If you want better durability the best spar is Epifanes. If it's too expensive a mid range spar I've had good luck with is Cabot spar varnish.

[John TenEyck]

Hey, at least your door doesn't get direct exposure to rain, snow, etc., just a couple of hours of sun. But that's still tough on clear finishes and if you got 5 years out of the original that's pretty good.

I agree with Edward; at this point your best and really only option if you want a clear finish is to strip what's on there off and start over. I've used Epifanes many times, and it's really good stuff, but takes a long time to apply the required 7 coats, more time than most folks have when rehabbing a door. As an alternative, I would strongly consider Target Coatings' EM-9300 Polycarbonate waterborne exterior varnish. Dries very quickly and gives a beautiful clear finish. Spray only, however. If you can't spray, then consider General Finishes Exterior 450 waterborne, which can be sprayed or brushed. Not as strikingly beautiful as the EM-9300 but still looks good and should be very durable for your application.

John

[Tom M King]

John, what nozzle size do you use for the EM-9300? That sounds like just what I need for Mahogany entry doors, and garage doors on my Mother's house, that I need to get done before the weather gets cold. Epifanes is the top of my old list too, but shorter finishing time would be extra good now, because the to-do list is long to get that house ready for rentals.

edited to add: I've never had any luck putting good finish over bad. The trouble is when the last finish fails, the wood starts to discolor, and more coating is not going to do anything for that. Even before the failure is obvious, the wood will start to mildew under the old finish, which means the only choice is down to bare wood.

[Wayne Cannon]

Often it's not the finish that is damaged by the Sun, but the wood surface beneath the finish. Depending on UV protection, Sun exposure will damage (oxidize?) the wood surface beneath the varnish, and this is what causes the finish adhesion to the wood to fail.

[Mike Walsh]

thanks for the comments and suggestions. Sounds like the General Finishes product may be a good option, I'll do some more research on that one. Thanks!

[John TenEyck]

John, what nozzle size do you use for the EM-9300? That sounds like just what I need for Mahogany entry doors, and garage doors on my Mother's house, that I need to get done before the weather gets cold. Epifanes is the top of my old list too, but shorter finishing time would be extra good now, because the to-do list is long to get that house ready for rentals.

edited to add: I've never had any luck putting good finish over bad. The trouble is when the last finish fails, the wood starts to discolor, and more coating is not going to do anything for that. Even before the failure is obvious, the wood will start to mildew under the old finish, which means the only choice is down to bare wood.

Tom, I can't remember exactly what the viscosity is of EM-9300 but it's low, low enough that I used a 1.0 mm N/N set with my pressurized HVLP gun. TC recommends using at least a 1.3 mm N/N but it sprayed beautifully for me with the 1.0. I'm using a gun with a PPS H/O cup running about 5 psi. With a gravity feed gun, the 1.3 mm N/N would likely be just right.

It should be a perfect product for your mahogany doors. If that's the route you take, please post some photos. They should look amazing.

John

[Adam Herman]

i am on year 2 on a vgf craftsman style door and it looks nearly brand new with Sikkens door and window finish. I used one with some pigment, as the pigment provides more UV protection than a clear finish. the door sees nearly full afternoon sun and only has a 2 foot overhang.

[John TenEyck]

i am on year 2 on a vgf craftsman style door and it looks nearly brand new with Sikkens door and window finish. I used one with some pigment, as the pigment provides more UV protection than a clear finish. the door sees nearly full afternoon sun and only has a 2 foot overhang.

Yes, the Sikkens (now PPG) Cetol Door and Window finish is amazing stuff. I used it on an exterior door facing directly West with no protection at all from the elements. Three years later it still looks perfect. That said, you MUST use at least two coats of one of the pigmented flavors of the stuff. They offer a satin clear coat, too, but that can only be used over the two colored base coats. Too bad there is no stand alone clearcoat option in this product, but the pigments are what make it work so well in the first place, so that's another impossible dream.


John

[Tom M King]

Tom, I can't remember exactly what the viscosity is of EM-9300 but it's low, low enough that I used a 1.0 mm N/N set with my pressurized HVLP gun. TC recommends using at least a 1.3 mm N/N but it sprayed beautifully for me with the 1.0. I'm using a gun with a PPS H/O cup running about 5 psi. With a gravity feed gun, the 1.3 mm N/N would likely be just right.

It should be a perfect product for your mahogany doors. If that's the route you take, please post some photos. They should look amazing.

John

I will. I hope we can get to them this Fall, but it may well be early next Spring.

[Scott T Smith]

Hey, at least your door doesn't get direct exposure to rain, snow, etc., just a couple of hours of sun. But that's still tough on clear finishes and if you got 5 years out of the original that's pretty good.

I agree with Edward; at this point your best and really only option if you want a clear finish is to strip what's on there off and start over. I've used Epifanes many times, and it's really good stuff, but takes a long time to apply the required 7 coats, more time than most folks have when rehabbing a door. As an alternative, I would strongly consider Target Coatings' EM-9300 Polycarbonate waterborne exterior varnish. Dries very quickly and gives a beautiful clear finish. Spray only, however. If you can't spray, then consider General Finishes Exterior 450 waterborne, which can be sprayed or brushed. Not as strikingly beautiful as the EM-9300 but still looks good and should be very durable for your application.

John

Great info John - thanks for sharing.

On a scale of 1 - 10, for a clear finish how would you rank the EM-9300 and the GF 450?

Scott

[John TenEyck]

Great info John - thanks for sharing.

On a scale of 1 - 10, for a clear finish how would you rank the EM-9300 and the GF 450?

Scott

A lot might depend upon the criteria you use for the ranking. Here's a list of several things I value:

EM-9300 GF-450 Epifanes Cetol
Type WB WB OB OB
Application Spray S or Brush Brush Brush
Dry Time 1 - 2 hrs 1 - 2 hrs 24 hrs 24 hrs
Time to Handle 1- 2 days 3 -4 days 3 - 7 days 3 - 7 days
Cure Time 2 - 3 wks 2 - 3 wks 3 - 4 months 3 - 4 wks
Clarity 9/10 6/10 8/10 8/10
Hardness 9/10 6/10 5/10 4/10
Scratch Resis. 8/10 6/10 4/10 4/10
UV Stability 9/10 7/10 8/10 9/10
Maintenance Interval ? ? 1 - 2 years 3+ years
Ease of maint. before film cracks 7/10 7/10 6/10 8/10
Ease of maint. after film cracks 4/10 4/10 4/10 Doesn't crack
Self chalking N N N Y
Blister Resistant N N N Y



The ratings are subjective, to be sure, based on only a few doors and outdoor furniture in WNY, definitely not definitive. If you asked me to rank order for use on an exterior door it would be Cetol Door and Window, EM-9300, GF-450, Epifanes. Of course, the Cetol Door and Window product is not a clear coat, but I added it for comparative purposes and because of it's amazing performance.. Let me also add that if you want the most bullet proof system available that would most likely be a 2 part polyurethane. It also would be the hardest to repair - nothing comes free.

John

Sorry, I can't get the columns to line up.

[Scott T Smith]

A lot might depend upon the criteria you use for the ranking. Here's a list of several things I value:

EM-9300 GF-450 Epifanes Cetol
Type WB WB OB OB
Application Spray S or Brush Brush Brush
Dry Time 1 - 2 hrs 1 - 2 hrs 24 hrs 24 hrs
Time to Handle 1- 2 days 3 -4 days 3 - 7 days 3 - 7 days
Cure Time 2 - 3 wks 2 - 3 wks 3 - 4 months 3 - 4 wks
Clarity 9/10 6/10 8/10 8/10
Hardness 9/10 6/10 5/10 4/10
Scratch Resis. 8/10 6/10 4/10 4/10
UV Stability 9/10 7/10 8/10 9/10
Maintenance Interval ? ? 1 - 2 years 3+ years
Ease of maint. before film cracks 7/10 7/10 6/10 8/10
Ease of maint. after film cracks 4/10 4/10 4/10 Doesn't crack
Self chalking N N N Y
Blister Resistant N N N Y



The ratings are subjective, to be sure, based on only a few doors and outdoor furniture in WNY, definitely not definitive. If you asked me to rank order for use on an exterior door it would be Cetol Door and Window, EM-9300, GF-450, Epifanes. Of course, the Cetol Door and Window product is not a clear coat, but I added it for comparative purposes and because of it's amazing performance.. Let me also add that if you want the most bullet proof system available that would most likely be a 2 part polyurethane. It also would be the hardest to repair - nothing comes free.

John

Sorry, I can't get the columns to line up.

Great info John, thanks much for sharing your insight.

[Mike Walsh]

I'm finally getting back to this door project (!) and was able to get the old finishes stripped, wasn't as much of a hassle as I expected. From the comments in the thread and some additional reading, I'm leaning towards using the Cetol Door & Window product for the new finish. From what I've seen the Cetol pigmented versions offer best durability, but the door was originally stained with Minwax cherry - no cherry pigment option for Cetol. Question - does it make sense to try to re-stain the stripped door with the original color (Minwax cherry) before applying the Cetol and i'm thinking the Mahogany color may be best over a cherry stained door?

[Jim Becker]

Keep in mind that the binder in the Minwax stain essentially seals the wood when it cures...which potentially can affect how the Cetol penetrates. Do a test piece to see if that's really how you want to go.