Need Help Acrylic sign faces going wavy...

[biggmann]

We have a couple new sign faces we have installed and the customer is complaining how wavy the sign faces are. When the acrylic came in and we cut down the face was flat and now that it is up in the sun its starting to warp. I know there is no fixing it but is there something we can do to prevent it from happening in the first place?

 

[Billct2]

How are they installed?

 

[ExecuPrintGS]

What thickness?

 

[michsanford]

And how big? Are they pan faces?

 

[Marlene]

need to know how large is the face? how thick is the acrylic?

 

[biggmann]

The sign faces are 24" high and about 18 feet long the acrylic is 3/16" thick and is held into the ex-7 frame extrusion with hanger strips across the top and bottom. The second sign face is 6' x 5' square held in the same way and same acrylic thickness.

 

[Billct2]

With that type of install I would check fit, if they are too tight they could warp when they get hot.

 

[Pauly]

hmm 610mm x 5486mm x 4.7m thick. (we usually use 4mm or 6mm)

Acrylic expands when warm. (this is why i love using glass) we usually use standoffs and allow play in the holes for movement.

 

[MikePro]

tight fit, depending on your acrylic. detail shows that particular extrusion has only a .156" channel to slide your acrylic into.
acrylic gets hot, wants to expand, but with nowhere to go uniformly then it will just squeeze itself wherever it can. Warm/cool/repeat, and you'll have wavy panels.

 

[dasigndr]

This 99% of the time is due to not enough expansion space in the face frame. For example if your face is 18ft long (height does not usually matter when most typical faces are 2ft up to 6ft high). Rule of thumb we use is, allow 1" of expansion for every 20ft. If for some reason the plexi is now shorter than the face frame and will probably slip out of the frame at one end, then you will need to add what we call an expansion moulding. See photo attached) Hope this helps.

 

[boxerbay]

would it have been better to use LEXAN instead of Acrylic?

 

[dasigndr]

lexan (polycarbonate) or acrylic will not make any difference as far as warping is concerned!

 

[IslandSignWorks]

3/16" seem really thin for a panel that's meant to be outdoors. Even for interior acrylic stuff we would double that or more. I'd have quoted that job in 1/2" 3030.

 

[Billct2]

This is a face in a box sign, 3/16" is fine.

 

[visual800]

3/16" seem really thin for a panel that's meant to be outdoors. Even for interior acrylic stuff we would double that or more. I'd have quoted that job in 1/2" 3030.

holy overkill! I wonder how many sign extrusion you have to redo to retrofit .5" acrylic where 1/8" was!

 

[ams]

3/16" is perfect for the thickness, 18' you may consider a 1/4". However use Polycarbonate instead of Acrylic. Also you can only get 18' as a roll stock, which is going to be wavy. The only real way to find a solution for that is to screw in one side of the face and stretch tight and screw in the other side (to the frame).

 

[oldgoatroper]

3/16" seem really thin for a panel that's meant to be outdoors. Even for interior acrylic stuff we would double that or more. I'd have quoted that job in 1/2" 3030.

Yikes! I hope you're just kidding around...

 

[Modern Ink Signs]

As AMS said, and I agree, you should be using polycarbonate not acrylic. I would have used .177 solar guard polycarb of this myself. I've done plenty of signs like this over the years and NEVER have had a problem. Just an FYI....

 

[TammieH]

3/16" seem really thin for a panel that's meant to be outdoors. Even for interior acrylic stuff we would double that or more. I'd have quoted that job in 1/2" 3030.

How many .5" thick sign faces have you installed in a standard sign cabinet/box?

 

[Melks]

I recently did a re-graphic on a 24 foot by 2 foot sign face. After re-installing the sign face with new translucent graphics the client was complaining about the acrylic being to wavy. You can see that the hot and cold temperatures affected the face and it looked worse at times. Whoever manufactured the sign I feel did a poor job of sizing the acrylic face as well the blow out strips were only about a foot long and were placed every couple feet along the sign. I've had others tell me it should have been a consistent blow out strip along the top and bottom of the acrylic face and not little pieces spaced out. (Not sure this would fix the issue as poor overall sizing I feel is the main issue) When the sign face was taken off the box and layed flat it didn't seem as if the acrylic was too large as it was not forced into the frame... As a business owner I want to keep my clients happy and I must say it's rather frustrating considering I am stuck trying to fix another manufacturers poor craftsmanship on this job. I am reluctant to remove the sign face again and try trimming so I have tried adding small clear acrylic shims in the backside of the acrylic face which has made the sign less wavy, but is not a long term fix. I didn't think these pieces of acrylic expanded and contracted so much...it's safe to say I'm learning from mistakes on this one!