White Haze Showing after a Couple of Years

[Marty Deslattes]

Hello!
We made 2 sets of shutters a couple of years ago for a customer. Both were stained and then had 2 coats of Minwax Helmsman Spar Urethane on them. The set that is under a covered porch are fine. However, the set that is more exposed has started showing some spots where wood is exposed (it appears probably where there were knots) and also areas where a white haze has developed. They are located south of New Orleans so alot of humidity and heat.

We are trying to determine what to do but want to make sure we don't end up with the same problems down the road. We stopped using pine for shutters. At the time, we used it upon request and this wood matched the customer's door. We currently only use cedar.

Any ideas on what caused the white haze? Do you think it is worth remaking using pine? Or should we just suggest replacing both sets with cedar.



Thank you for your help

 

[Ted Calver]

Marty, Welcome to the family. Glad you found us and hope you keep hanging out and sharing your work.

I am not a pro finisher, but am not shy about offering uneducated opinions. I've used marine spar varnish on a lot of boat trim and can tell you it needed redoing every few years because sun, heat and weather will triumph. You can tell from the good looking part of the shutter protected by the overhang versus the hazy exposed part. Pine probably didn't help. How have your cedar shutters held up? Same finish on them?

 

[Marty Deslattes]

I've learned how little I know about finishing after reading through this forum
We haven't had any complaints about the cedar and have had some ourselves for several years that haven't had this problem.
Someone mentioned it could be the sap from the pine - that the UV and heat draws it to the surface. They recommended putting unwaxed shellac over the stain and then the topcoat.

 

[fred hargis]

Your problem (IMHO) was the finish you used. Helmsman is a notoriously poor outdoor finish. It's urethane (problem #1) and urethanes never do well in a high UV environment. Then at least in some tests, it is lacking seriously in any UV inhibitor. Finishes resist UV by absorbing them (that's why they need maintenance) but in some test that Bob Flexner did he surmised that Helmsman had none...or an extremely small amount based on how poorly it did. My personal experience is that shellac also does poorly outdoors (I love shellac, but not outside). Bear in mind that any clear finish outdoors will need periodic renewal, an a true marine spar varnish will last the longest. A consumer level spar that has seemed to do well (after 2 years) for me is the Man 'O War spar varnish. But 2 years hardly makes it bulletproff. The true marine spar varnishes are expensive, but very worthwhile if you want long life.

 

[Dave Hawksford]

Lack of dryness in the wood when applied. Heat and Humidity getting to the finish. Did you seal the backs and bottoms of all the wood ? Helmsmans breaks down to fast , it SUCKS, We made the switch to Man-O-War exterior oil a few years ago. Never had any problems with our outside doors.

 

[Charles Lent]

In the Old Mystic Seaport, in Mystic, CT they preserve the old wooden ship rails and spars with a fresh coat of boiled linseed oil every two years or less. It stinks for a week or so until completely dry, but it seems to do a pretty good job.

Be careful about the fire hazards when using Linseed Oil though. Spontaneous combustion is a significant problem when using it, so don't leave linseed oil soaked rags around in a pile. Spread them out so the air can get to both sides of them. I hang mine from my neighbor's chain link pool fence for 24 hours (last house) or put them in a pail of water with a lid (present location), then wring them out the next day and then put them in the trash for city pickup. I burned my hand (not seriously) when I picked up a BLO soaked rag off my bench less than an hour after using it. I stopped to rearrange an area of my shop to prepare a place to put my project while it dried. It took a bit longer than I had expected. When I went back to the bench and picked up the rag, it was already about 160 degrees in the center. Had I not picked it up, it likely could have caught fire in another couple of hours.