[JOAT]

Guess this is the right place to post this. Eventually I will be making some house signs - with number. These will be placed on a stand - rebar or metal tubing stand on a tire rim - no telling how low it will take to get one done, my older son said he would weld it (he has had my welder for years), but it's been weeks now and no stand. He's "busy".

Anyway, the plan is to make several signs, hang one on the stand for awhile, then swap for another design. Which means it could be weeks, or months, 24/7 outdoors.

So, I need a protective finish on them. I don't recall ever making anything that would be outside 24/7 that was not painted. Normally I wouldn't ask, just put on a batch of layers of thinned Titebond II for a finish. But the Titebond would leave a sort of amber color on the white parts of the signs, and I don't want that.

So, need to know of something that will work. I've searched, a lot, mostly gotten conflicting info. Spar varnish seems to be popular, and I could live with that, but it's been 50-60 years since I last used varnish, and don't know if it would dry clear, or tinted, or not. I do want something that will dry clear, and will hold up for say 6 to 12 months outside, should be adequate, if I remember to swap the signs out. I like the idea of water base poly, but don't know how it would last outdoors. Oh yes, the signs will be 2 layers of 1/2" plywood glued together, with a paper design glued on.

So, any real life advice on this for me?

 

[MEBCWD]

Theo this should do what you want. It is also available in Gloss and Satin. There are other places you can buy it.

https://www.rockler.com/general-finishes-exterior-450-water-based-top-coat-semi-gloss

 

[DaninVan]

Theo; if you find something that actually does withstand weather, and I don't mean the manufacturers' claims, then please let us know. As I've mentioned before, our Parks people have been searching/researching for years!
Everything they've tried had to be redone within five years.
Spar varnish will be an orangy colour and will definitely need to be sanded down and refinished every couple of years. Epoxy may be your best bet(?).

 

[old coasty]

Theo,

I used Sikkens Cetol Marine on a boat for several years in a saltwater environment. I gave it another coat every 3 years without stripping., The boats with varnish were being stripped and revarnished every 2 or 3 years.

It comes in gloss or semigloss.

 

[Gaffboat]

It may depend on how much you're willing to spend, Theo. An outdoor finish recommended by professional sign makers is Sherwin-Williams Sher-Clear. It is a latex marine finish that does not yellow and is reported to last for years with a three-coat application. The downside? Cost. It's about $94 a gallon.

Sikkens Cetol, as Bob suggested works well outdoors, but I found it gave an amber color. The most commonly used finish for simple outdoor signs like yours is probably Helmsman Polyurethane Spar Varnish which is easy to apply with a brush or spray.

 

[JOAT]

Thanks guys. But been doing a lot more research, based on your suggestions, and seems there is a yellowing issue with most, if not all. So, more research. Think I found a answer suitable for me.
Olympic Waterguard 1 gal. Clear Multi-Surface Waterproofing Sealant

Meant for decks and such apparently. Got it from users, it does not yellow - or so they claim. Should work fine for me. Can get for $11.48 a gallon, from Home Depot, and I hate Home Depot. But, apparently Lowes does not carry it, Ace Hardware does, but none close, and their price is $15+ a gallon. Other places prices are even higher. So looks like I will bite the bullet and get it for $11.48 a gallon from Home Despot. Anyway, that beats $15 and up a quart of the other stuff.

 

[DaninVan]

Everything Shiny IIs Not Poly

Thanks guys. But been doing a lot more research, based on your suggestions, and seems there is a yellowing issue with most, if not all. So, more research. Think I found a answer suitable for me.
Olympic Waterguard 1 gal. Clear Multi-Surface Waterproofing Sealant

Meant for decks and such apparently. Got it from users, it does not yellow - or so they claim. Should work fine for me. Can get for $11.48 a gallon, from Home Depot, and I hate Home Depot. But, apparently Lowes does not carry it, Ace Hardware does, but none close, and their price is $15+ a gallon. Other places prices are even higher. So looks like I will bite the bullet and get it for $11.48 a gallon from Home Despot. Anyway, that beats $15 and up a quart of the other stuff.

Sounds like it might be plain liquid Acrylic.At that price not likely to be anything like polyurethane. I have a couple of gallons of liquid Acrylic waterproofing sealer here which I use occasionally for sealing; seems to work OK. Not sure how good a top coat it would be(?).
Rock hard when cured though!

 

[ger21]

Seal with several coats of thin epoxy, followed by several coats of high quality varnish. This will last longer than anything else.

 

[DaninVan]

I'm a big fan of the thin viscosity epoxy products, Ger

 

[DaninVan]

I'm a big fan of the thin viscosity epoxy products, Ger, but I think Theo was looking for an inexpensive product...that ain't epoxy!
https://www.go2marine.com/product/211310F/system-three-resins-s1-c-p-e-s-sealer-1-1.html


On the Acrylic emulsion thing...
Introduction: Acrylic Emulsions Market

Acrylic are the esters of acrylic acid and are formed from the reaction between acrylic acid and alcohol whereas emulsion are the colloidal suspension of a fluid in another fluid primarily in oil and water. Pure acrylic emulsions are broadly used in the preparation of a number of end-use products. Which includes architectural coatings, building materials, industrial coatings, glass-fiber secondary binders for tissues and veils. Water borne acrylic emulsions creates high performance coatings for various end use industries such as, printing ink, paper making and many more. Recently manufacturers are focusing on to provide advance technologies for the acrylic emulsions market as they providing more advanced formaldehyde free technologies or self -cross linking and also to focus on raw material selection for the acrylic emulsions. Properties of the acrylic emulsions plays a key role in the improvement of the quality such as it provides better coalescing properties than others. Growing responsiveness in regard with the hostile effects of VOC emissions, which is a primarily present in the solvent based goods, this has increased the demand for acrylic emulsion.
https://www.futuremarketinsights.com/reports/acrylic-emulsions-market

 

[JOAT]

Yep, want inexpensive, and doesn't dry amber. Otherwise I'd just use Titebond II thinned down. Several coats of that would work. This is for a project (house signs, with numbers), that will be for me, so not going with top quality stuff. If I were going to sell them (may later) would go with something a bit better quality most likely. But these will be out for a few weeks, then changed out for another sign, and so on. So it really won't matter if the finish won't last a year even, I'll have plenty of time to refinish them. At $11+ a gallon I am comfortable with experimenting with it. At $15+ a quart, not so comfortable - at that price it had darn well better work, and work well. It's the fact that I will have to get this from Home Depot, and I do NOT like Home Depot, that I don't like. Hmm, just recalled, Titebond has a clear glue. Might just call them and see if that would do what I want - that's how I got started using thinned Titebond II as a finish coat for a lot of my projects, including my canes - which are carried in the back of my pickup, in the open air, rain or sunshine. Holds up well.