I had another sign shop in the area pose this question to us: Hi Bill & Jane, We have a hi density foam sandblasted sign that we need to make. We have enough to do the job if we glue it, but in the past there has been a line where the seam shows up that doesn't look good. To do this job there would be 2 horizontal seams. Do you know of a way to do this without the seams being so obvious? What advice do YOU GUYS have to offer? Posted by Jerry Starpoli (Member # 1559) on :
There was a thread here a few months ago about salt and crazy glue, but I think that was more for small dings. I am sure someone here has the correct advice. I am curious as to the answer.
Posted by Kellie Miller (Member # 2788) on :
Hi Jane,
We have a one part urethane adhesive, PB Fast Set, that doesn't expand much. The reason why a lot of seams can be seen is because the joints are too big. (or adhesive is so much harder than the product, or too much adhesive was used.. all resulting in the same problem) When gluing 2 pcs. together, make sure to use just enough glue to change the color of the board and clamp so it doesn't make the joint bigger. Then sandblast like normal, and if any of the glue still shows, take a chisel or something and pock it out to match the rest of the background. I'll be happy to go into more detail or give other suggestions if you'd like. I'm sure you'll also get a lot of great ideas from all the talent on this site! (I actually heard about using the chisel from Gary Erickson at a Letterhead Meet in '97) Thanks, Kellie
Posted by Artisan Signs (Member # 3146) on :
Try Gorilla Glue instead of epoxy, it won't show as badly.
Posted by Joe Crumley (Member # 2307) on :
Jane,
Precision Board offers a glue just for this purpose. It is approximately the same density as their board. It's something like Gorilla but not quiet so dense.
Tell them, we're a great group of people and if they need an answer, there is always someone there that will help....
Posted by Jimmy Goines (Member # 5323) on :
Jane....from my experience, PB Fast Set is SO good on small hdu stuff, and also good on small redwood blanks...the "set up" factor is quick, but I've had problems with "PB-FastSet" glue bottle shelf life....
gorilla glue, like "poly-Urea" others just takes learning the polyUreathane glue workabilities, cleaning off "foam up" before or after, and seeing the gap filling abilities of the glue... sure works good on redwood also when the joints don't quite match well...
I say glue 'em, clamp 'em, squeegee the foam off, and let 'em cure... (it's a gettin' the panel blank ready thing...)
I ALWAYS have to sand the joints before further processes....the seams still stand after sandblasting, and I just cut 'em off with a knife or chisel...(like Kelly Miller says)
The polyUrea glue is also Really Hard to get off your hands and such, so I've learned to be prepared for that....Latex Gloves!!! (and don't scratch your schnozzle!!!)
[ January 07, 2005, 11:55 PM: Message edited by: Jimmy Goines ]
Posted by Cheryl Lucas (Member # 1656) on :
Hi Jane!
I haven't experiemented enough with it, but so far to me it 'seams' the nature of the beast!
I've followed the advise of what both Kellie & Jimmy have already mentioned and still, after blasting & removing the most obvious 'raised' glue seam, there remains a small 'wave' approaching each side of the later removed (obvious) seam. Hope this makes sense.
While sandblasting, the sand is hitting the harder area (the glue) and it is being deflected. This leaves a raised area on the HDU, on each side of the seam as well as the seam itself. However large or small the 'wave', possibly depends on how well the boards were squeezed/clamped together and how much glue is present during the blasting process.
I've picked, gouged and even taken a wire brush to these 'lil waves to some satisfaction. Then again, nothing's perfect...
Anyone else? What's your method to this maddness?
Cher.
Posted by Jeff Ogden (Member # 3184) on :
jane....
I am finding that being more careful with the (gorilla-type) glue application helps.
Looking at a board from the end, draw a line halfway up down the lenghth of the glue seam. Dampen the surface, and apply the glue to the lower half only. Why put it on the upper half, when you're going to be blasting it away ? Then clamp and let set as usual, then blast. You should now have very little or no glue showing.
A little way I have for disguising noticeable seams or dings, is as follows:
Take the sandblasted area in question, and clean it out good so you have a depression below the surface. fill with the thick, white filler that is the companion to Coastals WB-88 primer. Put on two coats,...the first will shrink, then the second should bring the surface a little higher than the surrounding area to be patched.
Now I take about a dozen small finishing nails, about 2", and slightly round the tips on a bench grinder or file. You just want to take away the pointy tip, kind of flatten them a little. Then take some masking tape, and wrap them into a tight bundle.
While the last application of filler is still moist, somewhere in between being wet and being too dry, take the nail bundle in your hand, and lightly tamp the surface with an up and down motion. This leaves little pock marks in the fresh filler, and if you watch what you're doing, it will make the patch look like the sandblasted background. Kind of rotate the nails a little as you tap, tap, tap. With just a little practice you can hide some serious scars this way.
This method works good for the rough blasted areas but I might add that I usually prime before I do any patching on the smooth surfaces of a SB sign...everything seems to work better, especially if patching a letter or smooth surface...then I usually prime twice before filling and sanding.
I hope this helps....
Posted by Jane Diaz (Member # 595) on :
Thanks for all the responses. I will forward this on the Ray & Rose. I have tried to get them to join in here....guess they are shy?
![[I Don t Know]](graemlins/dunno.gif)
![[Thanks]](graemlins/thanks.gif)