posted
The customer isn't ready to order it yet, but it looks like we might be getting to do that Fiddler's Cove job that I quoted on about 5 or 6 weeks ago. Huge sign for us. What is the best glue to use for edge gluing 2''SignFoam? I will need to make a panel 10' x 7'
One problem is that I will have to lay it sideways to get it through the 7' x 8' garage door of the shop. Then it will take up about 1/3 of the room. But, the thing that worries me most is that the joint will show after sandblasting.
Anyone have any experience with this? Thanks for the help.
------------------ "The most beautiful thing we can experience is the mysterious. It is the source of all true art and all science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: his eyes are closed." Albert Einstein
Failure to advertise is a lot like blinking in the dark. Nobody, but you, knows what you're doing.
posted
Hey, Wayne. PB240 will make the joint stronger than just the HDU itself. Are you backing it? You can use a smaill "veining" chisel to make the seam blend with the sandblasted area. If you're not using a grain-frame method and just sandblasting smooth or stippled, you can use a small cup chisel to hide the seam. I assume you're using a 5'x10' and adding to the top edge making the seam along the 10' length?
------------------ St.Marie Graphics & Makin' Tracks Sound Studio Kalispell, Montana stmariegraphics@centurytel.net http://www.stmariegraphics.com 800 735-8026 We're chiseling every day of the week! :^)
posted
Thanks Pierre, Yes the joint will be along the 10' length. I'm leary of backing the thing with anything like MDO because of how bad it warps and because I would think that the two materials would expand/contract at different rates.
The client has indicated that he might want it grained so this might make the joint less conspicuous too.
Can you back it with alumalite?
------------------ "The most beautiful thing we can experience is the mysterious. It is the source of all true art and all science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: his eyes are closed." Albert Einstein
Failure to advertise is a lot like blinking in the dark. Nobody, but you, knows what you're doing.
posted
Most of my murals are huge. ALL of them are backed with MDO, either 1/2" or up to 3/4" for the larger ones. Don't prime or paint the back of the HDU or the MDO side to be laminated. Use a 'cross-hatch" approach to applying the PB240 glue, and use screws all around the edges to keep it in place till cured. Turn the MDO vertical to overlap the entire seamed area. Screws all around the edges. Once the PB240 is cured, remove the screws. They're not necessary after a cure. If it makes you feel better, leave the long ones around the border in place. My largest murals are done just this way. There will be NO "breakaway" due to differing expansion rates. Up here where it gets -45 with no wind chill, and then a 60 degree change within a few hours, if any of them were going to delaminate, they would have done so years ago. Keep me posted. Call if you need help.
------------------ St.Marie Graphics & Makin' Tracks Sound Studio Kalispell, Montana stmariegraphics@centurytel.net http://www.stmariegraphics.com 800 735-8026 We're chiseling every day of the week! :^)
posted
Wayne, I should have mentioned, if you do use MDO, make sure the rough side is toward the HDU. (Glue bonds much better to the rough side with the unpainted HDU) I've sometimes used the smooth side to post copy. If the front was a "Vegas", sandblated greeting, I'd say "Come again, sucker!" on the back side.
------------------ St.Marie Graphics & Makin' Tracks Sound Studio Kalispell, Montana stmariegraphics@centurytel.net http://www.stmariegraphics.com 800 735-8026 We're chiseling every day of the week! :^)
posted
I have backed many HDU signs with Alumalite and it works great.
I have had great success with Gorilla Glue which is very similar to the glue Pierre mentioned. It blasts much better than epoxy and is easy to knock down with chisels or mini grinders to match the rest of the background. A GrainFraim blasted background will hide the seam easily.
------------------ Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 ICQ: 21604027 sherwood@up.net
posted
Thanks Dave and Pierre, Very good info. I'll keep you posted
------------------ "The most beautiful thing we can experience is the mysterious. It is the source of all true art and all science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: his eyes are closed." Albert Einstein
Failure to advertise is a lot like blinking in the dark. Nobody, but you, knows what you're doing.
posted
I have found that the PB Bond is the best for this lamination and I would avoid Ply as its durability does not compare to the HDU. The expansion, contraction coefficient of HDU, either SignFoam or Precision Board is roughly .00017, fiberglass .00014, aluminum .00012, Plywood .3 and expands bilatterally. If a thick enough and dense enough sheet of HDU is used, there is no backing needed. All sides must be painted to reduce breakdown of the urethane itself in UV.
------------------ Kent Smith Smith Sign Studio Greeley, Colorado, USA kent@smithsignstudio.com
Posts: 1025 | From: Estes Park, CO | Registered: Nov 1998
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posted
If you feel that you need to only stiffen the HDU panels, I've used a circular saw to cut a couple shallow slots in the back of the panel; then epoxied in an aluminum "L" strip.
If the shape is square or rectangular, an the sign is double faced, I've cut a deeper slot in the center of the edge of the sign and epoxied the alumimum strip in that way.
posted
Folks, I can tell you from hard, expensive experience that ANY real impact to an unsupported/backed HDU sheet WILL break! The mural in question was 4" thick HDU. We both paint and coat the MDO backing with Pelucid. This provides a permanent water seal. Even the large 8" thick mural for Glacier National Park on our website has offset MDO panel sandwiched between the double sided sign. By not providing a backing against impact flexing, you're simply "rolling the dice".
------------------ St.Marie Graphics & Makin' Tracks Sound Studio Kalispell, Montana stmariegraphics@centurytel.net http://www.stmariegraphics.com 800 735-8026 We're chiseling every day of the week! :^)
I just finished a 87"x38"x3" HDU sign. It will be mortised between two 6"x6" posts. I laminated 2 sheets of 1.5" thick HDU together with 2"x0.125" aluminum flat bar "splined" in. There are 6 bars run lengthwise in there.
posted
Waste of time? Of course not. With all those flatbars it should be strong enough to lessen an impact flex, but even the aluminum that thick can bend. That's the greatest risk with HDU signs. An unsupported area won't stand much flex at all. It simply breaks. Granted, it's pretty dense schtuff, but when the limit is reached, there's no "forgiveness" with the product. In the beginning, some years ago, I thought the fact of the density and apparent toughness was a real factor in eliminating the need for any kind of reinforcement. Not true. A slow steady flex doesn't appear to be a problem, but an impact and quick flex will break it. The whole thing is proportionate to the thickness and the amount of impact, but without that backing to prevent the easy flex, it WILL break. I wouldn't have believed that 4" thick panel could break, but when a gold cart roof gave it a gentle but steady push, it snapped clean in two pieces. Two pieces worth $1,300 each.
Oops. That's "golf" cart. It may as well have been a "gold" cart.
------------------ St.Marie Graphics & Makin' Tracks Sound Studio Kalispell, Montana stmariegraphics@centurytel.net http://www.stmariegraphics.com 800 735-8026 We're chiseling every day of the week! :^)
[This message has been edited by pierre (edited May 11, 2001).]
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