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Installing acrylic letters

gregsign

New Member
I need to install 3/4" thick solid acrylic letters (approx. 16" in height) to an interior brick wall. The customer does not want any holes drilled into the wall. Is there an adhesive that is strong enough to hold the pads of these letters to the brick without them falling off or becoming "un-adhered"? (They would be out of the way of curious hands touching or pulling on them)
Any recommendations are appreciated!
 

Ryze Signs

New Member
Lords acrylic adhesive or 3M urethane body panel adhesive would be strong enough. I would put some VHB foam tape in a few spots to hold it in place until the adhesive dries and put the adhesive everywhere else.

Yes they are big letters, but the bigger the letter the more surface area you have to hold it with adhesive.
 

monroesigns

New Member
Any adhesive used (whether it holds or not) will leave marks on the bricks if (and more likely, when) a change is necessary. As ProSign TN said, mortar joint stud mount will not damage the bricks, and it will be easy to drill into the mortar. Also, it is easy to repair holes in mortar.
 

signbrad

New Member
The first thing I do is ask such a client: "So, you're anticipating that you will be in business temporarily?"...Then I wait for an answer, giving time for embarrassment to set in. Or sometimes, I'll say, "If you were installing light fixtures, or an awning, would you not drill holes? If I want to be really snarky, I'll say, "What about a fire escape?" You gonna glue that up, too. And who knows, they may have a "good" reason to avoid penetrations in the brick.

At any rate, the industry standard, the "best practice," is concealed stud, screwing the studs into pre-threaded plastic glue blocks. A second, though less desirable method, is drill and tap the plastic itself. Using studs and glue blocks will also allow a small standoff, which can help you compensate for uneven bricks, allowing for an even, cleaner install. Uneven flatness against imperfect bricks is unsightly. Also, and this is just my opinion, a flat flush install looks more amateurish, like the letters were just "slapped" up. And the slight shadow caused by a ⅜ or ½ or ¾-inch standoff mount creates a "crisper-looking" letter edge. Again, my opinion.

There is no reliable adhesive for a flat acrylic-to-masonry mount. The letters will fall. Not all at once, but one at a time. They may break when they hit the ground, and there is an outside chance someone could be struck by a falling letter. Liability could be a selling point for stud mounting, by the way.

I never compromise on this. I don't glue plastic letters to exterior walls. I will pass on the job if the client insists on no penetrations. Then it can become somebody else's problem. What if they were channel letters? Are you going to glue them up, too? (That may even be a code violation). And what about a lighted cabinet? Adhesive only?

If you wish to go to the trouble, locate your studs so they all hit mortar joints. Then a repair of the holes after removal is similar to a tuck point repair. A standard brick, as well as a king-size brick, is typically 2½" high give or take, as I recall. A mortar joint may vary from ⅜" to ⅝", depending on the bricklayer. By and large, professional work by journeymen bricklayers is relatively standardized, unless they've got an apprentice on the job. A journeyman bricklayer is like a robot.

In my almost fifty years in signs, I have easily made more money off flat cutout plastic letters than anything else. Some substrates can be a problem, like shake shingles or coarse aggregate, but the work is never dull. It's always "fun."

Brad in Kansas City
 

rcali

New Member
As everyone else has said, studs are the way to go.

However, I did install 1/2 acrylic letters to cement walls about a year ago using VHB foam tape and clear silicone and they're still all up. They are very hard for anyone to reach though, so no one is able to pick at them/ try to steal them.
 

visual800

Active Member
yes it can be done with silicone BUT I like to scuff the backs and prime with 2 part automotive epoxy primer and hold the letter with gorill atape until it sets up. It would be nice since this is a .75" letter to have at least one studd per letter centered on letter just to be safe!
 

gregsign

New Member
The first thing I do is ask such a client: "So, you're anticipating that you will be in business temporarily?"...Then I wait for an answer, giving time for embarrassment to set in. Or sometimes, I'll say, "If you were installing light fixtures, or an awning, would you not drill holes? If I want to be really snarky, I'll say, "What about a fire escape?" You gonna glue that up, too. And who knows, they may have a "good" reason to avoid penetrations in the brick.

At any rate, the industry standard, the "best practice," is concealed stud, screwing the studs into pre-threaded plastic glue blocks. A second, though less desirable method, is drill and tap the plastic itself. Using studs and glue blocks will also allow a small standoff, which can help you compensate for uneven bricks, allowing for an even, cleaner install. Uneven flatness against imperfect bricks is unsightly. Also, and this is just my opinion, a flat flush install looks more amateurish, like the letters were just "slapped" up. And the slight shadow caused by a ⅜ or ½ or ¾-inch standoff mount creates a "crisper-looking" letter edge. Again, my opinion.

There is no reliable adhesive for a flat acrylic-to-masonry mount. The letters will fall. Not all at once, but one at a time. They may break when they hit the ground, and there is an outside chance someone could be struck by a falling letter. Liability could be a selling point for stud mounting, by the way.

I never compromise on this. I don't glue plastic letters to exterior walls. I will pass on the job if the client insists on no penetrations. Then it can become somebody else's problem. What if they were channel letters? Are you going to glue them up, too? (That may even be a code violation). And what about a lighted cabinet? Adhesive only?

If you wish to go to the trouble, locate your studs so they all hit mortar joints. Then a repair of the holes after removal is similar to a tuck point repair. A standard brick, as well as a king-size brick, is typically 2½" high give or take, as I recall. A mortar joint may vary from ⅜" to ⅝", depending on the bricklayer. By and large, professional work by journeymen bricklayers is relatively standardized, unless they've got an apprentice on the job. A journeyman bricklayer is like a robot.

In my almost fifty years in signs, I have easily made more money off flat cutout plastic letters than anything else. Some substrates can be a problem, like shake shingles or coarse aggregate, but the work is never dull. It's always "fun."

Brad in Kansas City
Thank you for the thorough input! I will try to convince the client into using studs in the mortar joints.
 

gregsign

New Member
As everyone else has said, studs are the way to go.

However, I did install 1/2 acrylic letters to cement walls about a year ago using VHB foam tape and clear silicone and they're still all up. They are very hard for anyone to reach though, so no one is able to pick at them/ try to steal them.
Thanks for the input!
 

tedshock

New Member
At any rate, the industry standard, the "best practice," is concealed stud, screwing the studs into pre-threaded plastic glue blocks. A second, though less desirable method, is drill and tap the plastic itself. Using studs and glue blocks will also allow a small standoff, which can help you compensate for uneven bricks, allowing for an even, cleaner install. Uneven flatness against imperfect bricks is unsightly. Also, and this is just my opinion, a flat flush install looks more amateurish, like the letters were just "slapped" up. And the slight shadow caused by a ⅜ or ½ or ¾-inch standoff mount creates a "crisper-looking" letter edge. Again, my opinion.

As you said, your opinion, but glue blocks for studs on the back of acrylic are NOT the "industry standard". If true, big players like Gemini and Steel Art would be doing it and they don't. Default is drill/tap, flush stud on acrylic (except 1/8" & 3/16"). Unsure how "glue blocks" helps with uneven bricks, because if the bricks are in fact uneven, then there is also the risk of having the stud glue blocks (which are all the same depth) sit uneven as well depending on the wall. We keep a variety of unthreaded nylon spacers in different increment depths ranging from 1/8" to 1", easily stackable on a flush stud setup. Mixing different depths allows a variety of compensation for uneven bricks. It also allows the standoff depth to be whatever works best for the color, typestyle, etc., to ensure the shadow doesn't affect legibility (which is esp. true for condensed black letters).
 

MikePro

New Member
if your customer is hellbent on not drilling into the block, maybe map out where the mortar lines are and place your studs there?
you could, however, use adhesives to mount like VHBtape & silicone as statedd above...but then you're still ruining the block. 2-3 holes per letter actually does less damage in the grand scheme of things, and will last much longer.
 

Moze

Active Member
Studs are a necessity at that size.

You might be able to measure the mortar line spacing and place studs on the letters accordingly, but the install world isn't usually that perfect. You'll likely wind up having to drill in the brick at some point because the mortar line fluctuates or something.
 

JBurton

Signtologist
As you said, your opinion, but glue blocks for studs on the back of acrylic are NOT the "industry standard". If true, big players like Gemini and Steel Art would be doing it and they don't.
Incorrect! It all depends, but yes, gemini will use either pads, blocks, metal inserts, or direct thread into thick acrylic for stud installation.
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Unsure how "glue blocks" helps with uneven bricks,
To provide the floating, as in not flush, look from the beginning. You'd need to individually adjust every letter until they are all within plane, but at least one letter or stud will be sitting against that acrylic block. Spacers can be used as well, but I'm a bigger fan of the block, as it provides all the functionality of the threading, and spacing, in a flat wall scenario. Plus you don't have to worry with Jimbo starting at the other end, neglecting to put his spacers or.
 
Lords acrylic adhesive or 3M urethane body panel adhesive would be strong enough. I would put some VHB foam tape in a few spots to hold it in place until the adhesive dries and put the adhesive everywhere else.

Yes they are big letters, but the bigger the letter the more surface area you have to hold it with adhesive.
Here is my problem with any kind of glue that is made to adhere to the acrylic.... What about the wall? The glue could dissolve or seep into the surface or paint on the wall and then it detaches from the wall with all the glue still adhering nicely to the letters.
 

signbrad

New Member
As you said, your opinion, but glue blocks for studs on the back of acrylic are NOT the "industry standard". If true, big players like Gemini and Steel Art would be doing it and they don't. Default is drill/tap, flush stud on acrylic (except 1/8" & 3/16"). Unsure how "glue blocks" helps with uneven bricks, because if the bricks are in fact uneven, then there is also the risk of having the stud glue blocks (which are all the same depth) sit uneven as well depending on the wall. We keep a variety of unthreaded nylon spacers in different increment depths ranging from 1/8" to 1", easily stackable on a flush stud setup. Mixing different depths allows a variety of compensation for uneven bricks. It also allows the standoff depth to be whatever works best for the color, typestyle, etc., to ensure the shadow doesn't affect legibility (which is esp. true for condensed black letters).
Tedshock,

When I started out in signs, flat cutout letters in thicknesses greater than a quarter-inch were rare. It may be that, back then, Gemini or Spanjer Bros. offered thick acrylic letters (1/2" thick or greater), with threaded holes in the backs. But I don't remember them if they did. The standard thicknesses for flat cutout letters were 1/8", 3/16" and 1/4". 3/16" was, by far, the most common. 1/8" was used for small letters, and 1/4" was used for flat cutouts in larger sizes, say, 24-inch tall and greater. This could easily be fact-checked if anyone has any old Gemini or Spanjer catalogs from the 60s and 70s.

Nobody drilled and tapped holes in the backs of acrylic letters in the dozens of shops I worked at throughout the 70s and 80s. At least, I never saw anybody doing it.

The practice of a sign shop commonly cutting acrylic letters in thicknesses of 3/4" or greater is fairly recent because the vast majority of shops had no practical way to cut the material in those thicknesses. Router tables were rarely found in sign shops till computers came on the scene. Letters were cut out with hand tools (sabre saws, jig saws, band saws, and Cutawls) and everyone purchased threaded glue blocks or threaded glue pads from suppliers like Gemini and Spanjer. Even formed plastic letters from these companies were mounted with threaded glue blocks adhered to the backs. Tiny threaded glue blocks were available for small letters, and larger blocks were made for larger letters. When shops wanted to produce letters with a dimensional thickness, they didn't try to cut thick acrylic, they just bought the formed letters. In the decades prior to computers, I never even SAW an acrylic letter 3/4" thick. Not that they weren't produced, but they were rare. Or maybe I just wasn't paying attention (that's what my ex would say).

By the way, one method for increasing production when hand-cutting acrylic letters was to stack the plastic. Cutting two and three layers was relatively easy, as long as you used premium cast acrylic. (If you used cheap acrylic, the letters tried to melt together at the edges). And you could cut four and five layers if you were slow and careful. I watched a guy at Hardin Signs in Peoria, Ill., cut six letters at the same time. Also, a table saw can make quick work of straight outside cuts on multiple layers.

Of course, computer-driven router tables changed everything. They have allowed even small and medium shops to cut flat letters in much greater thicknesses than were ever possible before. But is drilling and tapping the backs the default method for installing acrylic letters? For letters 3/4" or 1" in thickness, it is probably the most popular method, now. But drilling and tapping is labor-intensive, and acrylic in those thicknesses is expensive. I will still often use a threaded glue block on a 3/4" thick letter to avoid the tapping operation. I won't tap 1/4" inch thick letters—not enough threads. Again, my opinion, but a stud in a hole that shallow needs more threads to keep from breaking out of the hole. And from a mechanical standpoint, for strength, drilling and tapping the backs has no advantage at all over a threaded plastic block that is properly adhered to the back of a letter. A letter will break before a good glue bond gives way.

I think you made a valid point that a letter will sit unevenly on a brick wall whether it's flush or with glue blocks standing it off. Installing a line of letters all on the same plane is more due to the expertise of the installer rather than the attachment method. Personally, I have never, or rarely, shoved letters flat against a wall, whether glue blocks were present or not. I have always visually adjusted the stand-off distance a little, by eye, rather than always relying on the glue block or a spacer. Consequently, I rarely use spacers unless requested by a customer (or a boss). And from the standpoint of visual appeal, does a slightly visible spacer look any better than a slightly visible aluminum stud? I don't think so. The bare stud is thin, whereas a spacer adds thickness, making the support more visible, not less visible, right? So why would a spacer be better visually? I have, on rare occasions, painted studs a color close to the wall color. And obviously, using spacers to get a consistent distance from the wall is difficult on very uneven surfaces, like shake shingles or coarse aggregate, sometimes next to impossible. On corrugated metal walls, trying to cut spacers in multiple lengths can be frustrating. So why use them? And if a stud hits a bevel, what then? Spacers are not worth the trouble on corrugation. Just trust your eyes to get all the letter faces on the same plane.

Brad
 
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