Sikkens Cetol vs. Spar Urthane

[wa3cuj]

I am in the process of staining the interior wood on 32 Peachtree double hung windows. It was suggested that I go over the stain with an exterior clear finish to protect in the event that there could be some condensation on the widows during the heating season.

One supplier recommends Sikkens Exterior Door and Window Cetol satin finish (a product I never heard of) and another supplier recommends using Helmsman Exterior Spar Urethane.

Does anyone have experience sufficient to say that one is superior to the other?

Thanks.........Bob

[Edwin Pawlowski]

I used Cetol on some outdoor furniture and I don't care for the color change. It did not go on as smooth as regular spar urethane either. I'd certainly try some on a scrap piece first to see if you like it. I'd not use it again.

[Charlie Morgan]

There are many variants of Cetol, and not all of them are pigmented. The nice thing about Cetol is that it breathes. A problem with polyurethane varnishes is that they do NOT breathe, and so if any moisture manages to get under it, it lifts the varnish off. Cetol doesn't have that issue.

CWM

[Edwin Pawlowski]

This one was not pigmented, but like all oils and coatings, it did make some color change. My Helmsman polyurethane coated stuff is holding up much better than the Cetol Marine recommended by the paint dealer. Maybe that breathing is allowing the moisture in making it worse. Perhaps a different variation would have fared better, but after one poor experience I'm not going to try it again. It was also very expensive for poor performance. .

[Charlie Morgan]

I use it on the exterior teak on a sailboat (salt water) and it is extremely durable and easy to maintain.

CWM

[Jon]

replying to wa3cuj, Jon wrote: Just read ur text. I've had great results from sikkens prolux... I believe that is an exterior product. When dealing with moisture, temp changes ,UV, it has excellent resistance to weatherimg and wear. I have found using stain or any pigment on exterior wood covered with spar urethane either the moisture, solvent entrapment, UV????? Seem to cause bridging and checking within several years...? If you get a good substrate" freshly removed coatings, sanding , washing , remove any mill glaze causes by filling grain with old finish. 2~3 coats of sikkens is great! After sanding and removing all prev coatings then scrub with water and TSP...then. lightly a and with 180 and apply 3 coats...

This will guarantee ggreat results... Not for I exterior apps!!!! Use poly or varnish.?