Posted by Ben W. Collins on October 30, 2002
D. BernhardtI am needing help on the referenced subject. I have made a 4ft X 8ft sandblasted sign for our start-up church property and plan to paint the letters and logo. The blasted area is beautiful and I would like to finish it with a material that waterproofs and protects it from potential fungus and UV damage but retains much of its natural look. Sikkens has some film forming products (Cetol 1 & 23) that I could possibly use. Thompsons has several products in this area also. Does anyone have any recommendations.
Kent SmithHi all...Have been doing the following for quite a few years now with good success. Sikkens stain to the colour you want followed with AT LEAST 2 coats of the TGL varnish from same company. They have several finishes. IE: satin flat and gloss and have found that the satin looks great at installation time but will flatten right out after a year or so. The gloss will tone down to satin in a year and for textured backgrounds like blasting or carving will look terrific. Also you can add one-shot or what ever over top with what I can see so far (thank god) is no failure! The probs with using #1 and #23 was that the 23 would start to cloud after a few years. No prbs as mentioned with the Tgl
Mike JacksonA little late clarification: clear waterproofing helps only to preserve the overall integrity of the wood but the surface silicates from the product breakdown in UV in 9 to 12 months. The Sikkens clears are about the best wood finishes on the market but it is true that their life is about 3 years, maybe 5 with multiple coats on more solid finished woods such as scaved logs. Any finish on carved or blasted wood is at a disadvantage since the surface will move greatly with expansion and contraction. Even the long grain acrylics such as waterborne UV clear will break down under these circustances. Having said that, the acrylic will double the life, whatever that might have been. Only pigmented finishes will protect redwoods and cedars from graying out, no clear or waterproofing will stop that.
I looked over the answers already given, and agree with what has been written. The only time we had any success with a clear finish was for interior signs, signs under the downtown canopies, and a few signs that faced North that wouldn't get the long summer sun. The transparent stains worked as well as anything, but it does not have a gloss or semi-gloss finish. We actually painted most of our redwood signs with latex in a variety of colors, and those outlasted the stained ones. We did a test using a few different varnishes, stains, and latex paints and put it out on the roof for a year. We used that sample when customers wanted varnished signs...and once they saw the examples, the immediately switched over to paints and stains.
Ben W. CollinsI use oil based stains for backgrounds and find them to hold true for many years. There are some anti fungal additives, but most stains already have this in them. I use an oil based fast primer on the parts to be painted and usually get a coat or two of enamel on them before applying the stain. Then wipe the enameled surfaces and apply finished coat.The textured surface will hold up better this way than with any clear.
Rick: I am using KILZ oil based primer and One Shot lettering enamel. Will use your system and apply the last coat or two of enamel after I cover the blasted background.
Spielman, in his book (which is the only book I could find and was written in the 80's) says to load it up with waterproofing which, of course, will not protect from UV.
Have you ever done this and, if so, what was your experience? I know it will turn gray and wonder how the wood would survive.
Thanks again for your good info.
Ben W. Collins
Raymond ChapmanMike: Have you ever just put the cedar sign out with no stain? Spielman (the only book I could find) says to just load it up with waterproofing material. I know it would turn gray within a few months although it will face north. His book is probably outdated since it was written in the 80's. I don't know how the wood would survive, though.
Thanks a lot for your help. My wife and I enjoyed the pics of your family, incl. the beautiful dog. Looks like you have the good life.
Joe CrumleyIn my opinion there are just not too many clears that are going to hold up against the sun unless you use one of the two part automotive clears.
In the past when I have wanted to retain the natural look of the wood I have used a semi-transparent stain (my choice was Olympic - mainly because it was available locally) in a color that was close to the color of the wood. Since I was using redwood, I used a redwood stain and it made the wood have a more uniform appearance and protected the wood at the same time.
In following the threads on various Bulletin Boards there seems to a strong urge to put clear on just about everything. To me it just doesn't seem practical to cover up one film with another in order to make it last, especially when the clear normally breaks down before the paint or vinyl film. Just a thought.
I must agree with Raymond on this subject. For years now I have tried to preserve the color of cedar and redwood with a variety of clear finishes with no longlasting success.
The problem with the two part automotive clear is that it is a very hard finish and will fail, crack, when the wood expands and contracts. It really shabby when this happens.
I too would dearly love to solve this problem.
I have a wooden sign in front of my shop that was clear coated fifteen years ago and is still looking good. It does not have a sandblasted background though. The textured background would have too much movement for that type of finish. There are clears that are made to apply to redwood houses to preserve that fresh pink look. Some of those clears last almost a year. I don't remember the name of the current hot one, but last year it was DuckBack. These finishes contain alot of silicone and make it so it might require many years before you could get anything else to stick to it. I've never been real pleased with that option.
Ben W. Collins
Joe: I haven't found anyone that has a product that will do the job for me. The Sikkens people say theirs will last 3 - 5 years but, it requires 3 coats to get this protection and you have to sand or clean w/ TSP and wash with a pressure washer in order ot recoat. It also colors the wood darker as a stain. This material is used on log houses.
What have you done, if anything, to protect your WRCedar signs. I may just use waterproofing and let it age gracefully.
Thanks for your response.