Not HDU Again "CRACK"

[joe]

We did a U turn when I saw this one.



Don't you know the sign company who sold this sign told the City of Roswell they were getting a fool proof material that will last for years!

This sign was 4"X4'X10' and what do you know it's CRACKED. Most of us using these materials have found the best way to use them. We've glued aluminum, angle iron, and MDO in HDU trying to overcome it's weaknesses.

I've come full circle by returning to wood as the major substrate for all my signs. The only time I use HDU is for detail carving on logo's and lettering.

The helmets aren't part of the sign.

Joe Crumley

[sebago_signworks]

Joe, not sure if it the climate or not, but we dont have too many issues with HDU here. I have many 4x6' signs, hung in-bewteen 2 poles using steel as the brackets that have been up for years now. One of the few changes I have made on double sided signs using HDU is instead of using one sheet for both sides, I will use two 2" sheets with alumalite as the core. So far (knock on wood) we have not had any HDU failure. That being said we were in Southern PA (Pittsburg) going to W. VA on a job and we noticed multiple HDU signs that did not hold up. Maybe here in the north the elements dont effect HDU the same way it does where the sun shines brightly all year long.

[joe]

Sounds like you've done well with this product however there are limits.

HDU takes special techniques when using screws. Screws expand and contract, HDU doesn't which leads to failure
It will not span distances without interior braces.
Paint preperation is a true pain.
It's way too expensive.
Outside borders will not take any abuse and if the interior is exposed UV will does damage.
Do Not glue up one sided sign with DiBond. It will warp like a potato chip.
You can not refurb an old HDU sign because the material gets brittle.

Gees I could go on for ever. But, what every material you choose has thumbs up over here. Should I show more photo's of HDU failure?

Now don't get me wrong I use Duna. I have a 6K order of 20lb. That will be for small exterior signs on a present job.

Joe Crumley

[sebago_signworks]

When it come to inserting screws, we ream the hole a bit and insert epoxy to allow for expansion/contraction. I agree with the paint, we use the 18lb foam which is a bit easier to paint with Matthews or House of Kolor which gives it a nice look. Even then you do see a dimple or two..three. Never used di-bond, Signfoam recommended alumalite. It has worked well. I wouldn't do more then a 4x6' before going back to wood or another substraight. I do agree with your theory... there is a place for HDU. Wood is king. I am still looking for alternatives to Acrylic for raised lettering/etc. Lots of people using PVC which I am unfamiliar with and would like to learn more about.

[joe]

O well here is a 5K job that went wrong with DiBond and HDU. I posted on this when it happened and was told I used too much glue. You Sure! The brand name isn't important. All of these panels are made the same and expand at a different rate than HDU. I'm sure you know that. Good to see your pocketing for screws. That's essential








I'm not sure you can tell the amount of warpage by the last shot. I could have let it go for a while to make a point but I'm not wanting to punish a customer. We've made five of these and scared to death there will be more failure. All are at ground level and student damage may be an issue. When I make these from Redwood or YP they are much tougher. And I don't worry about them.

Should I post more HDU catastrophes? OK I will.
The one thing I'm trying to do is protect Sbers from errors .

Joe Crumley

All the maroon letters are cut from 1/4" PVC and glued down with silicone.

[sebago_signworks]

Very nice sign... And dont get me wrong Joe, I dont disagree with HDU is a pain in the ass. We used Alumalite due to its 6mm thick vs Di-Bond. Also, its hard to tell in your pic but we never mount HDU into wood, we always use steel as a buffer for expansion and contraction. Wood and HDU have different expansion rates. Also over time if the wood checks it will warp, leaving your sign warping with it. Its allot of work, but in the pics below we would have a steel brace to mount to the poles, then mount the HDU to the steel. The steel can handle the shift/check of the wood that the HDU cant. And the Steel and HDU have a similar expansion rate. I have allot of respect for you Joe, and look forward to meeting you at SignCamp in June... Im not picking a fight! You forgot more about the sign business then I ever knew! That being said I can see some room for failure where the HDU and the wood are mounted together with no buffer. Somebody made a SF sign down the road from us, used steel against wood, the top of the sign extends about 30" above the steel and come to a peak, its all warped above the steel??? That sucks I would like to see S.F.'s answer to what that happend. I think its only been there for 2/3 years now. We have been lucky.
[IMG][/IMG]

I know its hard to see in these pics, but we have steel to buffer the wood and hdu.

[sebago_signworks]

Joe, the background in the University sign, is that blasted with a grain frame or similar or CNC'd? And the lettering, looks like 1/8.. what is your choice of material for that?

-----Joe, sorry just looked at your post again and saw it was PVC...

[joe]

I also see MDO and HDU glued together all the time. Like you, I've never felt comfortable with that process but I have to say it seems to work. The important thing HDU needs special attention or it will fail. I'm expecting to see lots more along this line.

I'm glad were having this discussion because I know there are Newbees who need to know.

Newbee's won't be making signs like mine because the process is too involved. And If you haven't seen someone making up large panels it would be tough. They will have to go with board like materials.

For me HUD is a three letter word!

Joe

[knight_toolworks]

Joe your ok with pcv as letters and such glued to a backing board? of course they have to be painted right? what paint sticks to pvc the best?

[joe]

Steve,

That's the great thing about PVC, I haven't seen any paint that won't stick to it. I like good old flat house paint. Except on dark colors. For that I use OneShot with their hardner.

Devin,

These signs are routed. No sandblasting.

Joe Crumley