Best “no finish” finish for cypress Adirondack chairs to combat mold/mildew?
Hello everyone. My first post on this forum and glad to be able to join.
I just completed a set of Tom McLaughlin’s beautiful Adirondack chairs for my outdoor patio, and they came out great (got lucky and found some really clear cypress). My plan was always to leave them unfinished and let them age naturally to the grey that cypress does.
To my dismay, however, after just three days outside, and being rained on a couple of times, mildew formed on some spots that looked just terrible! They are back in the shop now and I have cleaned and sanded back the affected areas.
So… I am searching for a light, as invisible as possible, sealing finish that will prevent this rapid mildew growth, and doesn’t change the natural look of the cypress. Ideally one that I can spray with my HVLP system. I understand that I will need to update whatever I put on them.
Multiple coats of thin shellac? A commercial deck sealant? Penetrating oil? Fungicide additives?
Any and all advice/ideas are greatly appreciated and thanks in advance!
Tom S.
Replies
Wood outdoors needs frequent attention. There's no avoiding it. Paint is your best option.
Whatever you do, don't waste your time with shellac outdoors!
There is a new marine wood treatment that gives excellent results on teak and looks like there is no finish on the wood, it is watery and requires annual maintenance, no stripping just cleaning and re-coating. It’s called Semco.
Teak sealer,, not oil,sealer.. other than that I ve had good luck with TWP clear but it's an oil ,some change in look. It will look oiled. I haven't tried it but Penofin has a product called Verde --stain or clear ,no smell ,for exterior or interior and reading about it sounds like you can use it for salad dressing! I varnish a lot, takes time for sure and must be maintained. Stay away from hardware store versions like Helmsman. I like Epiphanes or Tonkinois .
I've used cypress a bunch for outdoor stuff. The myth is that it doesn't need protected. It's all a myth for everything. Teak maybe for a boat deck. Dulls out grey and the last thing you want on a deck of a boat is slippyslidey from some finish but they get cleaned regularly. If they don't they'll turn green like anything else. All wood that sees weather needs some kind of protection. Don't paint those chairs-- well maybe in 10 years or so!
I use Penofin Oil on my outdoor furniture, I usually reapply every 2 years. It does have mildew protection. You can spray it but not sure if you can spray with a HLVP system, just call the company I have found them very helpful when I had a question.
Those Tom McLaughlin chairs look like a lot of fun to build.
Good Luck
Good luck
Thank you all for your detailed thoughts. Really appreciate it. Much to consider. Has anyone had experience with General Finishes Outdoor Oil?
To follow up, I'm going with Penofin Ultra Premium Red Label Penetrating Oil. The folks at Penofin were very helpful. I put samples of their clear and "cedar" color stain on some test pieces of cypress and put them outside for a week. Held up well, but I know that's not very long. They advertise good mildew resistance, 99% UV protection (50% with the clear, so I'm using the cedar as the color difference is minimal), and you *can* spray it with an HVLP system. Fingers crossed. Thanks again!
I think you will be very happy with the results. I have been very happy with the product and the service.
Not a direct response to cypress but I purchased western red cedar Adirondack chairs (we call them Muskoka chairs in Ontario) four years ago.
Unfortunately the build quality was crap, rather disappointing for a long established outdoor furniture builder, but the cedar looks great.
I have not treated the wood at all. It has a nice even patina, no microbial damage. I redesigned the arm rests this spring and the colour now completely matches.
A red cedar chair this size is heavy enough to not wander when you sit in it and light enough to move around the patio when needed. Good qualities.
I anticipate 20 years from the chairs, maybe a new screw here or there 10 years from now, and NO paint or wood treatment.