Replies

1. 
   SteveSchoene | Jun 14, 2007 03:26am | #1

   Rustoleum (the parent of Varathane) is one of the consumer companies that doesn't seem to want people to know what is really in the cans you buy.  As near as I can tell from the web pages, the Natural Oil Finish is an oil/varnish mix.  This will be the case if you read the instuctions on the can and they say to wipe on, let soak for a few minutes, and then wipe off.  It will build no film leaving very natural looking wood, though the finish will add little in the way of protective properties.

   I believe the second product (black can) is Professional Clear Finish oil based.  This is pretty clearly a fast drying varnish.  It will build a film, but that film will not be well suited for wide temperature and humidity ranges of exterior applications, and if the door gets any sun during the day, will likely fail and have to be stripped and redone a relatively short time. 

   If this mahogany door is for exterior use, neither of these products is suitable in any way. 

1. 
   wilmore | Jun 14, 2007 05:42am | #2

   Steve, I appreciate your advice.  Yes, the door is an exterior entry door and will get some late afternoon sun.  You say neither of the Varathane oils would do -  is there another oil finish that you'd recommend?

1. 
   SteveSchoene | Jun 14, 2007 12:18pm | #3

   Why an oil finish?   UV protection requires thickness in the film.  With an oil finish, even one with UV absorbers added, there is virtually no film thickness.  This means that maintenance needs to be very frequent, with light sanding and a new coat applied every few months.  For me, that would be a lot of work to keep mahogany looking great--and why pay $3,000 if that's not the goal. 

   Were it my door, I would use a good marine spar varnish, which, with only afternoon sun, can probably go two years between maintenance coats.  There are three good brands of marine spar varnish.  Epifanes Clear High Gloss, Interlux Schooner, and Pettit Captain's.  You will find these at boating supply places, such as West Marine or Boater's World.  On line, http://www.jamestowndistributors.com or http://www.defender.com would be reasonably priced sources.  Nonetheless, expect to pay $25 per quart.  The manufacturer's directions call for 6-8 coats of full strength varnish, and boaters know that this is necessary. 

   Some longevity may be added by using a low viscosity epoxy under the varnish to reduce moisture transfer.  Smith & Co. makes one that is available at Jamestown Distributors.

   For the house I am having built now, I will forgo the mahogany in favor of a good, smooth surface, fiberglass door that will be finished with a high quality gloss enamel.  That door probably will go 5 plus years before needing recoating.  

    

    

    

2. 
   beachfarm | Jun 14, 2007 03:09pm | #4

   Varathane Professional (the black can) is an excellent finish. My finish supplier had a closeout on four 1-gallon cans of the gloss finish at $9 per can. I bought one thinking it would, at the very least, make a good shop varnish for tool handles, work tables and the like. It turned out to be a VERY good varnish. Dries quickly and sands like talc. Sanded back and rubbed, it gives Cherry the finest out of the can finish I have ever worked. Truly. The remaining three cans now sit in the finish locker.

   Would I use it as an exterior finish: NO.

   I get an annual run of marine jobs that range from simple refinishes to replicating worn or missing parts to the fabrication of custom parts. The finish I swear by is one that Steve mentions: An epoxy undercoating with a marine varnish topper. I use West System epoxies but there are many good brands. 3 coats to the raw wood, wet sanding between coats. After the third coat, your material is encapsulated (that's your water barrier). Varnish top coats provide the UV protection. For a varnish, I use Interlux. 4 to 6 coats on a vertical surface is fine. More for horizontal surfaces or for any part in constant exposure.

   There are a number of issues to have in mind if you go this route. My top two are:

   • You will need at least two weeks for this finish process. 24 hours per coat for epoxy. 24 to 48 hours per coat for the varnish. It's not a quick finish but it will last for many, many years. When it's time to restore the finish, you need only restore the varnish and, usually, only the top two coats.

   • An epoxy/varnish coating will build considerably so keep the clearance of the door to the jamb in mind. Too tight a fit will crush the finish between the door and the jamb and you will not like the results. And speaking of weather strip: vinyl, closed cell foam and/or rubber strips will react with (and ruin) the varnish until the varnish has fully cured.

   Here's a marine grade Mahogany ply hatch for a 18' Whaler built to replace the original Teak ply hatch. The boat sits in the local harbor, exposed to the elements, all day everyday...

   
   

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   Edited 6/14/2007 8:15 am ET by beachfarm

   
1. 
   beachfarm | Jun 14, 2007 03:17pm | #5

   Let's try that again...

   
2. 
   Ron01960 | Jun 14, 2007 04:05pm | #6

   I agree with Steve, 100%. I just sold my house in Feb. I had double, raised panel mahogany doors. I used the best quality marine varnish I could buy. About 30.00 per qt. A product from Holland, I don't remember the name, sorry.I scraped the doors (exterior only) and surrounding trim with card scrapers, to bare wood. The interior of the doors and trim were just like new after twenty five years. The man who finished them after installation used some kind of urethane. I saw the empty cans in the trash. I had supplied the marine varnish, his excuse was it took to long to dry. I made two temporary screen doors to have assess while I had the doors on the bench. This was a summer job, so I could start at sun up and go until I dropped. Its amazing how much the doors weigh when your working in 90* days for 12 hours or more. Going to work on Monday was a welcome relief.The plus for me is I live near the coast, and I had several high end boat yards in which to seek answers. They only used the highest quality varnish. Apply at least 3 coats probably four the first time to raw wood. The first coat was reduced 10-15%. Lightly sand between coats. 200 hrs. The raised panels had too much detail for my taste after the arduous task, I had a new found appreciation for less detail on the exterior. Ron

3. 
   KiddervilleAcres | Jun 14, 2007 04:32pm | #7

   I will be replacing the wood plate that is part of the dashboard in my boat.  I'm planning on using solid white oak.

   Thanks to you I now have a finish schedule for it that I have been mulling over for quite some time.

   Thanks for the info.

   Regards,Bob @ Kidderville Acres

    

   A Woodworkers mind should be the sharpest tool in the shop!

3. 
   BilljustBill | Jun 15, 2007 07:38pm | #8

      Wilmore,

     I'd use both the oil and then the film finish.  Like the fellows said, the oil finish will go into the wood, but there's not much buildup.

     When I built a writing secretary and bookcase, I originally finished it with several applications of the Varathane oil.  After letting it dry for a week, it just needed some extra depth.  I then finished the furniture piece with three coats of Deft.  The oil provided a very enhanced grain, and the Deft sealed it.  Rubbing the last coat of Deft with 4-0ught steel wool, the finish is deep and smooth.

      Your door would need the hard Varathane film finish , but first applying the Varathane oil would make that Mahogany look like a Million!

     Here's a picture of the project and its finish,

      Bill

   
   

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   Edited 6/15/2007 12:39 pm ET by BilljustBill

   
1. 
   SteveSchoene | Jun 15, 2007 08:09pm | #9

   Oil/varnish mix is fine for popping the figure, but, I'll reiterate that whenever an object (the op has an exterior door) gets direct sun it takes a special finish to achieve any durability.  That's why my list of acceptable marine spar varnishes in an earlier post.  Brands you can buy in big boxes or ordinary paint stores just are not up to the task of direct sunlight.