I just built 2 Adirondack Chairs made out of Honduran Mahogany. I have never used this wood species before. I would like a clear natural finish to preserve the natural beauty of the wood and obviously protection from the elements.
I have to admit I have little knowledge of finishes other than general stains and protective coatings that I used on some inside furniture pieces bought at a local hardware store.
I am thinking of using Spar Varnish. Should the wood be sealed prior to putting on the varnish? Is spar varnish a good idea? I would also like to try spraying the chairs to save some time and I have a one quart can of spar varnish in my shop. Can a spar varnish be sprayed?
Any help would be appreciated. It would be a shame to wreck such beautiful chairs that I made.
Replies
If you can, wait until the next issue of FWW is out. There is an article in it about outdoor finishes. We left a bunch of different finishes outside for 1 year at a few locations around the country. The article tells you, among other things, which ones protected the wood the best. The issue will be out by the end of the month.
--Matt
I think I will wait to see the results. I have invested both money on materials and my time so I think I can afford to wait a couple of weeks. Thanks for the feedback.
Yes, you can use spar varnish, but realize that it is a high maintenance finish, requiring an additional maintenance recoat about every year, and occasiional stripping and refinishing. If you do decide to use spar varnish use ONLY high end marine spar varnish from boating supply stores, in general it is it's own best sealer, though a low viscosity epoxy to aid in moisture proofing applied under the varnish may be able to extend the life somewhat--note that is to be under the varnish, the varnish is necessary to protect the epoxy. No such marine varnish product, regardless of the nautical sounding name, is sold at the Big Boxes or ordinary paint stores. Follow the directions on the can which would call for about 5 or 6 full coats at a minimum. And, since it is a gloss finish, the slick surface may not feel so good if you sit on them in shorts.
My choice would be to not finish the chairs at all, letting them naturally weather to a mellow grey. They will need an occasional scrub. I would coat ground contact surfaces with epoxy, but epoxy doesn't stand up to UV light very well.
Another choice is to make Sunbrella acyrlic fabric covers to protect them from sun.
I will be looking forward to the new article testing outdoor finishes.
thanks for the help. The gloss finish could be an issue as you stated about the feel if it wearing shorts. I might leave one chair unfinished and finish the other chair based on the article comming out at the end of the month. See which one gets used more by this time next year.
Once thing I forgot to mention is that I live in the Houston area with lots of humidity and sun year round.
If you really want these to look nice, I would use Epifanes spar varnish AND make the covers as Steve suggested. No clear finish, regardless of quality will last when exposed to the sun. And,,,, once it starts to peel, it's all over but the shouting and you'll need to sand all the way back to wood for the privledge of doing it all over again. I know this because I have a boat with lots of wood trim. No matter what you do, if exposed to the sun, the finish is toast in a year unless you scuff sand and re-coat. Even at that, it will eventually fail and you'll need to start from scratch. And, oh yeah, when it fails and starts to peel, it looks like hell.
Some 12 years ago, I made a custom tiller for my boat laminated from oak and mahogany. I applied probably five coats of varnish. Although it seemed a little anal retentive at the time, I made a sunbrella cover for it. 12 years later, it still looks good. I wish I could say that same for the exposed wood that was re-finished just last year.
I have seen sunbrella covers for toe rails and the like. They were held in place by small velcro dots, and a few ties of light line where possible.
I really am not a rude person. I don't like to seem harsh , but I can't believe you used South American Mahoghany on an Adirondak chair. That stuff is for building heirlooms- not porch furniture.
Frank
Edited 4/7/2009 9:36 pm ET by Biscardi
Mahogany is a fine outdoor wood, a traditional marine choice, and dramatically less expensive than teak. So why not make an heirloom Adirondack chair?
I wanted a durable wood that looks very nice. I looked at rough cut Teak but the cost was prohibitive in my area. $27 b/f.
I also got tired of building pieces on the cheap using ratty old wood just because it was cheaper. In the end I was not happy with the way it looked, knots everywhere, warped etc. It was time for a change so I invested a little more in the materials. I also built the exact same chair out of Cypress and I have to say I will spend my time in the Mahogany one.
I got what I wanted. The piece is very comfortable, looks great and I will enjoy many hours lounging around in it.
South American Mahogany is an excellent choice for this project. You would be quite shocked to see how many porches and decks are made with mahogany. It's quite resistant to the elements, and isn't that expensive at all compared to teak, Ipe, etc.....
The last batch of Mahogany I used was $6.25 a bf, all 5/4 stock. I don't consider that expensive at all compared to some woods that are $15 plus, plus....
To each his own. If you want to use mahoghany for outside stuff that is Ok. It is a disappearing resource and I think it is best used minimally on really fine work.- see attached
I built a portch out of blacklocust that is gorgeous and cost about $1 a foot. It will be around until Gabriel blows the horn.
Frank
What are the botanical names for this "Honduran Mahogany" and "South American Mahogany"-as far as I know SA Mahogany (aka Mogno) is not the same as what Biscardi talks of.
I wouldn't dream of using pukka Mahogany for an outside project, and neither is the Mogno stuff as I know it suitable for outdoor use.Philip Marcou
>> What are the botanical names for this "Honduran Mahogany" and "South American Mahogany"Here is a snippet from Wikipedia:"The name mahogany is used when referring to numerous varieties of dark-colored hardwood, originally the wood of the species Swietenia mahagoni, known as West Indian or Cuban mahogany[1]. Mahogany was equally applied to the wood of Swietenia macrophylla, which is closely related, and known as Honduras mahogany."Cuban mahogany has been generally unavailable for many years and is considered endangered.Honduran mahogany is plantation grown in a number of Central American countries as well as a number of northern South American countries.Both American mahoganies are listed in the Forest Products' Laboratory Wood Handbook as "Resistant or very resistant" to decay which means they are excellent choices for outdoor applications. African mahogany is listed as "Moderately resistant" so is less desirable for outdoor use.Howie.........
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