How would you fix push through letters?

[signfab]

When fixing intra cut or push through acrylic letters to a light box face I've never had much luck fixing the face letter to the backing acrylic without producing shadows from the joins in clear VHB or the leafing effect from using acrylic cement.

How do you fix these letters?

 

[Zendavor Signs]

The shadowing shouldn't be too noticeable from a normal viewing distance. If this is viewed up close you could use 3M 467 adhesive so it covers the entire letter with no seams. Or you could rout the push thru letters and backing out of a single piece of thick clear plex.

 

[Andy D]

I did the whole Bank of America push through program, and we did that by routing 1" polycarbonate down
7/8" and leaving a 1/8" thick "shoulder" about 3/8" wide around each letter, meaning, no gluing together two pieces of plastic.
Does that make sense?

 

[signfab]

Thanks for the replies.

Zendavor, 3M467 sounds like a good idea I'll have to find out what the largest roll is as I will also have a 4' Dia logo to do.

Andy D, I've tried this method before. Once bitten twice shy as the shoulder didn't provide enough surface area for adhesion and the letters eventually let go and fell in.

 

[J Hill Designs]

Andy D, I've tried this method before. Once bitten twice shy as the shoulder didn't provide enough surface area for adhesion and the letters eventually let go and fell in.

make the shoulder larger

 

[fixtureman]

The ones I did for some companies I used the whole sheet and didn't have a problem

 

[Zendavor Signs]

Thanks for the replies.

Zendavor, 3M467 sounds like a good idea I'll have to find out what the largest roll is as I will also have a 4' Dia logo to do.

Andy D, I've tried this method before. Once bitten twice shy as the shoulder didn't provide enough surface area for adhesion and the letters eventually let go and fell in.

I would highly recommend using studs for mounting, not just adhesive. Here in the US you can rent one for about $150 or so. It is well worth the extra money.
Also, don't do just "shoulders" - cut it all out of 1 piece if you can.

 

[Moze]

One piece letter/flange, attach flange with studs/nuts (slightly oversize holes in flange), Lexel perimeter of flange.

 

[signfab]

Thanks for all the suggestions, I'll look at the cost of having them routed in one piece.

 

[Andy D]

Thanks for the replies.

Zendavor, 3M467 sounds like a good idea I'll have to find out what the largest roll is as I will also have a 4' Dia logo to do.

Andy D, I've tried this method before. Once bitten twice shy as the shoulder didn't provide enough surface area for adhesion and the letters eventually let go and fell in.

It looks like others beat me to this, but yes, like everyone else said, you can make the shoulders as big as you like.. 4" or more all the way around, if needed.
This really is the best method, you don't have to worry about blotchy adhesive showing through, or any other type of adhesive failure.

The Bank of America faces probably wasn't the best example, the reason we kept the shoulders so narrow was because it was plastic push-thru letters with a translucent plastic
face and we didn't want thick shoulders shadowing through.

 

[Tel]

We do exactly the same as Andy D we route a shoulder on the letters or logos or whatever, we work in metric my shoulders would be 10mm wide that's nearly 1/2 inch and have done lots and lots of them and never had a letter fall in, but we make sure we use a good quality 2 pac glue.
Also it's an added safety feature if the routed and letter does detach it will fall in as it is to big to come out of the routed aperture in the light box, therefore it will not fall on any people. I have seen an acrylic letter glued to a large flat acrylic base inside the light box and the letter had fallen off and was lying smashed on the sidewalk not our work by the way. We would never do a light box any other way, the job looks quality because there's no shadowing from glues and it's also double safe.
Make sure you use a quality adhesive.
regards
Tel

 

[rossmosh]

Properly glued acrylic should not "fall apart". We're not talking about a small surface area here. Something like Weldon 4 should not fail. Using something like Weldon 4 and not getting any bubbles is a bit more tricky.

I'm working on starting doing this type of sign, but I can say with 100% certainty that it's going to cost a heck of a lot more to do it out of 1 piece instead of doing flanges or applying to a backer board. Your sheet yield is going to drop dramatically doing it this way and you're machining time will increase as well. It really boils down to preference, skill set, and to a lesser extent, economics when deciding whether or not to do a flange or a backer board from what I can tell.

Also, take this with a grain of salt, but maybe you can use gravity to your advantage. If you install the box with a slight pitch, gravity will help keep the letters in the box. Obviously I'm talking about a slight pitch as anything more than that would be noticeable and potentially look really bad.