Last year we built a new helibase, that has exposed glulam beams on the exterior.
Per the contract specs, they were coated with three coats of Old Masters Spar Varnish. And, the finish had severe deterioration in the first year.
We would like to apply either more spar varnish, (or something else, if anyone has suggesstions), to protect and seal the beams.
I have two questions:
1.) What prep do we need to do, prior to placing more coats?
2.) Are there other brands of Spar/Marine varnish that will hold up beatter?
Replies
In my experience with boats, spar varnish works better in theory than in practice.
I know,
I would have specified log oil, like they use on the log homes here. Reapply once a year, and it lasts forever.
But, it wasn't my design, and now I have to try maintaining what got installed.
The first year's deterioration may have been less to do with the spar varnish (brand or material) and more to do with inadequate prep. Were the glulams dry or dirty? What temperature was the material applied? Were the manuf. application specs followed? Construction projects have a habit of skimping on last minute details.
They were wrapped
We kept the wrapping on, until we stained.
The beams were left over a long weekend, the subs worked four tens, so the stain went on Thursday, and was allowed to dry through the weekend, weather was clear and warm to hot, relative humidity between 10 and 20%.
The Spar varnish was applied in three coats. On Monday, the first coat was applied and the wood, sucked up the varnish. The yeild was only about 80% of the manufacturers recommended area per gallon, of 150-sf.
The first coat dried overnight before the second coat was applied on Tuesday, it went on at the 150-sf/gallon the manufacturer recommended.
The second coat dried overnight, and the third coat was applied on Wednesday. The yeild on it was at 147sf/gallon.
I don't know what else could have been done.