I recently was gifted a session at a Board and Brush establishment, and made a lettered sign which I wish to hang on the garden fence. I would like to preserve it with a waterproof topcoat. Suggestions for product? The board was stained first, then painted, then lettered. I don't want the waterproofing product to alter the result. Thanks for assistance!

The lettering is flat, no 3D. I wonder if spar varnish would be a good option. Am a little leary of chemicals/health issues with auto clear (that I read in some other forum).

  • Fair warning, it's going to be very difficult or impossible to get a long lifespan out of what you've made. Making a durable product for this purpose generally starts with the choice of substrate and then proceeds through the prep and finish stages (basically, good primer and then suitable paint). Trying to achieve the same end after the fact is sort of like trying to close the barn door after the horse has bolted. Possibly the best result would be obtained by spraying with automotive clear coat, but if the surface is 3D it will be very hard to coat it evenly.
    – Graphus
    Mar 16, 2019 at 16:04
  • I agree, that were I doing it at home I'd have done it a bit differently....but I just need to add a bit of durability even it it lasts just a few years. I figured to use a spar varnish or other topcoat, but wonder about how it will dull the sign. It is a flat sign, so no 3D.
    – SME
    Mar 16, 2019 at 16:15
  • OK well flat surfaces certainly simplify things. Spar varnish (a marine grade, not the stuff sold at the big-box store) would definitely waterproof your sign, and it's the first thing most woodworkers will think of, but unfortunately it violates one of your stated requirements since it will alter the result — there's a significant colour to spar varnishes and after you apply the requisite 3 or more coats you'll get a huge amount of added yellow/amber.
    – Graphus
    Mar 17, 2019 at 7:18
  • I doubt this suggestion will be any more practical than the automotive clear coat but it just occurred to me that you could wrap the thing in fibreglass, just as done in canoe manufacture. The thin glass-fibre sheet becomes pretty much transparent when impregnated with resin, imparts no colour, and forms a 100% waterproof skin.
    – Graphus
    Mar 17, 2019 at 7:19
  • Did you ever get this resolved? If so, please give a check-mark to the answer that helped you the most, or write up your own answer explaining what you did to get it fixed and give yourself a check mark. That will help others with this kind of problem know that this has a resolution and is a good place to look for their answer
    – FreeMan
    Jul 29, 2020 at 14:44

2 Answers 2


If you want it to be bullet proof, surfboard epoxy will definitely waterproof it, and it will last for many many years. I've epoxied a 14 foot mahogany wood boat. You have to work in small batches, as the larger the batch the faster the cure, but its neat stuff. I used System 3 when I did my boat.


Ive had good luck with this: Genereal Finishes Outdoor Oil

But your results will vary, depending on regional climate.

  • 1
    Maybe expand on why you think this specific brand addresses the question, and maybe provide a description of what sort of generic finish this brand represents.
    – user5572
    May 22, 2019 at 17:09
  • For what the questioner wants, he needs two qualities; UV and water resistance, and a water clear finish. Most solvent and oil finishes are amber tinted. Any outdoor formulated (low permeability and high UV resistance)water clear finish will work. The one I suggested is but one. Minwax makes a hybrid oil\water based poly (Pro Series Outdoor Urethane)that also works well and is available through Lowes or your local hardware store. The Helmsmen series of spar varnishes don't hold up around here and are amber colored, anyway. May 28, 2019 at 14:05
  • 2
    I mean, expand on it in the Answer to make it more complete. The idea is to build up some Q&A not just for this person, but for future visitors. Assume the special brand you mention will be unavailable in the future.
    – user5572
    May 28, 2019 at 14:46

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