Clear coating for glulam

Archive of Older Topics Archive - Product Discussions #5
1

I looked up the Bio Clear product data sheet, which is here for anyone else to do the same:

http://www.epoxyproducts.com/data810.pdf

The product data sheet states the following:

“Unless top-coated with a UV absorber, this epoxy will yellow and eventually turn cloudy with exposure to
sunlight.”

A direct contradiction to Jim’s “simple facts” about epoxy coatings.

I then called the manufacturer and was told that this product is not suitable for use as a clear coating over exterior glulam beams if color change, chalking, and yellowing are not desired.

The XTR-20 product is evidently unavailable to the public, because I can find no other reference to it outside of the surf board web site the qoute came from. I sincerely doubt that if it is a product that is available that the manufacturer would recommend it as a product suitable for use on exterior glulam beams.

2

Anon - I noted the yellow fact about Bio Clear in my post above. You state you “looked up the Bio Clear Data Sheet” as if it was a piece of technical research or a revelation - but you provided the website link.

Your “research” doesn’t change the fact that somehow it’s promoted as non-yellowing as I noted.

The surfboard comparison is perfectly valid. Epoxies, polyurethanes, polyureas, precatalyzed lacquers and other technical products have found extensive use outside their original focus.

My point was the technology for non (or reduced) yellowing epoxies exists. If you choose not to believe what others have presented that’s your right - but please don’t contradict people who have provided proof of technologies you don’t know about. Perhaps researching them would have more value, and if you find hard evidence that the products mentioned do not exist or perform as claimed, great - if something is not as presented I’d like to know about it.

But just saying “it doesn’t exist” proves nothing.

I don’t mind being wrong (and I am all the time - just ask my wife!), but I don’t accept simply being told “you’re wrong” by a source who refuses to identify him/herself and provides only anectodal (“my rep says…”) or isolated product performance (“this epoxy”…) as "proof.

Example of isolated (and completely invalid) “proof”:

"“Unless top-coated with a UV absorber, this epoxy will yellow and eventually turn cloudy with exposure to
sunlight.”

A direct contradiction to Jim’s “simple facts” about epoxy coatings."

You are taking a single product and making an assumption of fact (a “proof” with insufficient evidence) that an entire technology works precisely the same way. That’s the type of invalid proof taught in high school debate classes (as one of the most important things to avoid)..

“THIS EPOXY” (emphasis mine, noting a statement commenting on a single product) is NOT a contradiction to facts about “epoxy coatings” (PLURAL - and a technology encompassing thousands of products).

Sorry, but your isolated “facts” don’t prove anything.

And not that I’m king of coatings (far from it) - but at least I’m an open book. What’s your coatings-specific background and training?

3

From West System about their epoxy system used as a clear finish over exterior glued laminated members, from their technical department:

“It is not intended to be used as the coating by itself for outdoor projects. It can be used as a clear base prior to applying exterior varnish or automotive clear coats or UV stabilized marine clear polyurethanes. We do not offer a warrantee associated with this process because it is not intended as a final clear coating for exterior finishes and how well it holds up depends a great deal on the quality of the UV stabilized clear coat applied over it.”

4

And from their Product Data Sheet for 207 Special Hardener:

“An ultraviolet inhibitor in 207 helps provide a beautiful, long lasting finish when used with quality UV filtering varnish.”

Yes, it does say “with a UV filtering varnish”. However, the material DOES contain an UV inhibitor , which WILL (as does any UV inhibitor) reduce and/or slow the effect of ultraviolet light on the epoxy, and in areas NOT directly exposed (or exposed only for short periods) are also non-yellowing components. Coat a park bench that’s in sunlight all day and even a supposedly non-yellowing polyurethane will yellow and discolor.

But coat a beam or soffit not directly exposed to sunlight with a UV-inhibitive epoxy and you will not have the yellowing (and sometimes darkening of the underlying substrate) of old-technology epoxies.

By the way, which product did you pull that from? Oddly, I didn’t find it anywhere in the 105/207 product data.

And thanks for again not bothering to offer the slightest bit of credibility. Colin has project experience with the product and years in the industry; I have decades in paints and coatings. As a “lowly Specifier” (your words, Mr. or Ms. Anon) what’s your depth of knowledge of epoxy systems, other than your mentioned phone calls to reps (who may or may not be experienced in epoxy chemistry)?

We could go back and forth like this for years, but it’s a waste of bandwidth. New technologies exist - you just need to research them. I’ll be happy to do the research and advise you myself if you’ll identify yourself; if not your wasting everyone’s time “trolling”.

5

Let’s recap:

  1. It was suggested that clear epoxy coatings would be appropriate for use on exterior glulams.

  2. It was also suggested that this is not the case.

  3. Several products were suggested in support of point number 1.

  4. In accordance with each of the suggested manufacturer’s technical data, NONE of the suggested products are appropriate for use as a primary coating over exterior glulams - - in the case of Colin’s suggested product, that manufacturer EXPLICITLY states that this is not a warranted use of the product (even WITH a UV protecive coating over the top). Call them up yourself if you still don’t believe this. It’s like 5 minutes of your time.

  5. The bottom line is that clear epoxies do not perform well for very long when exposed to UV (sunlight). It’s not a question of IF failure will occur, but WHEN. Failure in this case means chalking, yellowing, turning opaque, etc. - it’s an appearance issue.

  6. Could clear epoxies be applied over exterior glulams? Of course! But in doing so an ADDITIONAL layer (or layers) of UV protection is required to slow/prevent the appearance change of the epoxy (assuming that another CLEAR layer of something is applied - which is the entire point of this thread - a CLEAR finish over exterior glulams.)

  7. Would I recommend to an Owner that TWO clear coating products be applied over exterior glulams just so I could get an eopxy coating in the mix? Probably not - since there is no advantage in doing so (and no warranty from at least one manufacturer). I am not writing specs for a boats or surfboards. A high quality clear polyurethane coating is really all that is called for in this case, and there are several on the market warranted for use directly over exterior glulams without the added complications and cost associated with trying to shoehorn a clear epoxy somewhere in there.

By the way, I didn’t take Colin’s posting as an endorsement of that manufacturer’s products for use over exterior glulams - but if that is how it was meant (or interpreted) all should know by now that this is not something the manufacturer will recommend or warrant.

end

6

Hmm…maybe we should take a litle closer look at that recap -

One known poster has project experience (successful) with a particular product. An unknown person calls the manufacturer (who makes products primarily for another industry), finds they won’t endorse such installations, and somehow seems to think that means the project must not have happened (at least that’s the only conclusion I can come to).

“two of the projects the product was used on were glulams on high end homes, at least one of which is in Laguna Beach, right near the Ocean. It was used as a general coating for glulams on at least 2 projects and there have not been any issues.”

Mr./Ms. Anon, despite your phone call - please do yourself a favor and read the preceding paragraph again.

Another is a coatings veteran who is aware of resin technologies not necessarily used in production products by the big-name manufacturers.

Note - reps do NOT normally know about new technologies and products in development. If you have never worked for a coatings manufacturer on the management level you probably would not know this. Companies do not want reps selling things until marketing can “do their thing”, which involves testing and sample applications for “credibility”. It’s quite time consuming and secretive - but it does NOT mean you can’t get the product.

A large regional manufacturer (since sold several times) at one time had 4 or 5 times as many special-order, “unknown” products as cataloged products. There were many very advanced, unique techology products made for odd or test applications - I should know, I had to price every single one!

More recap - examples were provided (and the application/industry is irrelevant in this case, as these resin technologies are often introduced to the construction industry after being found elsewhere - as Richard did with the West system.

Evidence was provided that UV-inhibitive and resistant epoxies exist.

The question regarding gulam beams in the shade was ignored. Hmmm.

A manufacturer used as an example of “it works” was called by our anonymous person (who refuses to provide a shred of credibility) - and this person claims the manufacturer would not back an application with UV exposure.

Well, duh - they’re in the boat epoxy business. But this is how advances in technology are made - if a product works on a boat, a Specifier suggests it may be a good choice for an architectural application - and it works.

If unique installations of construction products were never attempted we’d be living in caves.

The mystery person calls a “trusty rep” who is unaware of new technologies.

What a shock. See paragraphs above.

Industrial coatings manufacturers are called by the same person (we assume) and don’t have non-yellowing epoxies for UV exposure.

No surprise. See paragraphs above.

Mr./Ms. Anon - all you seem to have proved is your scope of resources is a bit limited and you refuse to think out of the box.

I will give you a similar example of “that won’t work” and/or “never heard of it” technology - polyurea membranes…especially as underwater waterproofing and parking deck coatings.

"Polyurea? That’s truck-bed liner. You can’t use THAT on a building or industrial application.

That was the naysayer reaction 15 years ago. I now refer you to www.pda-online.org.

I was at the Orange County CSI Chapter’s annual product show/seminars - the first part of the seminar session concerned building envelopes - and there were some newer technologies discussed; there was also some minor grumbling in the crowd along the lines of “we’ve never done it THAT way!”

Anon, welcome to some “new ways”. Of course, it’s your choice to ignore them. I think it was Satchel Paige, though, who said “don’t look back - something might be gaining on you!” A phrase you might think about a bit. BTW, I’m not annoyed - I just think it’s sad when progress is stifled (and heck, I’m one of the “old guys” in the coatings world!).

So even though I’ve been doing this stuff for decades I learned about some products I was not familiar with - that also prompted me to investigate other manufacturers, in and out of the construction industry. Why? Because if there’s been a successful application something must have gone right, and if so I want to know more about it. I’m going to keep looking ahead.

It’s a shame you won’t.

(I have to say I cannot figure out what the motives are for “denying advancement”, coupled with a refusal to identify oneself.)

I think that’s enough for me on this one - I’m not going to continue trying to help someone who refuses to BE helped.

“Anon”, if you would like to continue this for some reason, please contact me off the forum - I won’t respond here so no more forum time/bandwidth is wasted on a discussion that apparently has no resolution.

-out-