Laminate HDU to HDU (&/or MDO) w Titebond ?

[Doug Allan]

Hey all, it’s been awhile since I’ve worked w HDU, & even longer since assembly of multiple HDU elements on one sign.

I’ve used gorilla glue before & struggled to use enough clamps, or not use too much glue, so the expanding quality of that glue makes it not my first choice on this project.

I’m doing a 60” diameter Maui County Logo, and will have a 56” diameter MDO backing panel to bond everything to, and provide a better mounting structure.

The sign will be indoors, and some of the assembly will be much easier with a slippery wet glue that allows precise aligning, after bringing two pieces into contact with each other.

Can anyone confirm in wood glue is a good choice for these bonds, under these conditions?

I’ll add a progress pic if I can remember how to do that on my phone

 

[Kottwitz-Graphics]

My first thought was why don't you machine out the background and leave the copy as part of the rout file, rather than cutting the letters, and bonding them on after. But the more I look at it, the letters, the outer circle with the "rope" element, and the inner circle, are the only thing routed, and the back layer is just what, flat HDU cut into a circle?

I believe I would use west systems epoxy to hold it, and then use a screw from the back side to add a mechanical fastener as an extra little bit. And I would avoid any assembly in the field. I would want a completed sign ready to install on site. A lot of times, I will go to the hardware section, and I'm not sure what they are called, but Stanley makes them. It is a short flat piece of metal with several holes already punched, to attach (2) items together... I rout a small slot on the back, and attach it the included screw (if it doesn't protrude thru the face) and then pour in some west systems epoxy and sand it smooth. That gives little mounting tabs to install the sigh with.

 

[TimToad]

We use Titebond 2 Polyurethane glue to adhere the HDU to whatever backing panel we're using. It expands like Gorilla glue but not nearly as much.

 

[Doug Allan]

Matthew? Man it’s been a while mr. Kottwitz, so forgive my guess if it’s wrong

The 56” diameter MDO backing will be covered by HDU, because I had a 3/4” sheet and a 1/2” sheet on hand, so my rope border is 1-1/2” thick at the edge but the backing ring is a 2” wide “ring”, (cut from 4 pieces) to fit around the MDO, bringing sign diameter to 60”, but with only foam edges to seal up & paint.

In the pic, if you notice some yellowing on the thin veneer of 1/2” foam under the letters, it helps to see the seams where there are 4 quadrants that fit around the pictorial center.

I guess my logic in this much-assembly-required approach is that a 60” HDU sign would have some seam no matter what, and shipping HDU to Hawaii is not cheap, so using what’s on hand, but avoiding a seam through the pictorial (which would be harder to hide) led me to this design. Plus wanting MDO for strength, but not showing at edges.

Editing to add that the 1/2” thick HDU rings under the letters, have a shallow pocket router to receive the letters, giving me luxury of quick accurate placement (after easy pre-drilling for screws, when needed) and most of all, I hate hand painting 3D letters that rise up out of single routed foam. Spraying the letters & then adhering them suits my brush skills much better...

 

[Kottwitz-Graphics]

Matthew? Man it’s been a while mr. Kottwitz, so forgive my guess if it’s wrong

The 56” diameter MDO backing will be covered by HDU, because I had a 3/4” sheet and a 1/2” sheet on hand, so my rope border is 1-1/2” thick at the edge but the backing ring is a 2” wide “ring”, (cut from 4 pieces) to fit around the MDO, bringing sign diameter to 60”, but with only foam edges to seal up & paint.

In the pic, if you notice some yellowing on the thin veneer of 1/2” foam under the letters, it helps to see the seams where there are 4 quadrants that fit around the pictorial center.

I guess my logic in this much-assembly-required approach is that a 60” HDU sign would have some seam no matter what, and shipping HDU to Hawaii is not cheap, so using what’s on hand, but avoiding a seam through the pictorial (which would be harder to hide) led me to this design. Plus wanting MDO for strength, but not showing at edges.

Editing to add that the 1/2” thick HDU rings under the letters, have a shallow pocket router to receive the letters, giving me luxury of quick accurate placement (after easy pre-drilling for screws, when needed) and most of all, I hate hand painting 3D letters that rise up out of single routed foam. Spraying the letters & then adhering them suits my brush skills much better...

Mark, actually, but I've been called worse...yeah, it has been a while...

That actually makes a lot of sense... And having the pockets is a good idea, I typically don't pocket, just because unless your using a really small diameter bit, or the letters are rounded, there will always be a little bit of a fitment issue...but I'm also using a 35 year old (assuming) Baby Gerber AR660 Router, that like me is a little cantankerous, and you have to "massage" its ego to get it to do what you want...

As far as the Titebond Poly glue that Tim suggested, I have no experience with it. I know that one of the foam manufactures makes a glur got their foam, and I have a small bottle here, but I have yet to use it, but I can't for the life of me remember what it is...

 

[Billct2]

We have used acrylic polyurethane adhesive that comes in a tube for chaulking gun. Doesn't expand and stay workable for a while.

 

[Doug Allan]

We have used acrylic polyurethane adhesive that comes in a tube for chaulking gun. Doesn't expand and stay workable for a while.

Thanks Bill!!
There is nothing like a referral from a known peer with direct personal experience!

 

[Z SIGNS]

On a sign like that we would some kind of nice cleat. Frame on the back of the foam,frame on the walI. stopped gluing HDU to another substrate a long time ago.When we use HDU today it's a robust shell around a frame. Have had failures in the past. Especially with gluing to MDO on a 2 sided sign.Rots out quick HDU moves a lot. need to look at the expansion of the disimilar material before you decide what glue to use.Gorilla glue for example dries hard and take little movement.

 

[Doug Allan]

Here’s a look after getting more of the painting done. I bought a caulking tube of polyurethane adhesive, but so far nothing is bonded yet, just set up for the pic

The second pic shows my 2 layers of 3/4” foam at edges, hiding the plywood core

 

[Johnny Best]

Did you ever get rid of that HP printer giving you so much trouble? Good to have you back.

 

[TimToad]

Here’s a look after getting more of the painting done. I bought a caulking tube of polyurethane adhesive, but so far nothing is bonded yet, just set up for the pic

The second pic shows my 2 layers of 3/4” foam at edges, hiding the plywood core

Will the seams be concealed somehow?

 

[Doug Allan]

Did you ever get rid of that HP printer giving you so much trouble? Good to have you back.

That day the thing bled out all it's cyan, the day before my flight to burning man 2 years ago, was the last day any ink flowed from this shop... dumped that thing & been outsourcing ever since

Will the seams be concealed somehow?

To the best of my abilities, with spackle, sanding & touch up paint...

 

[Billct2]

That day the thing bled out all it's cyan, the day before my flight to burning man 2 years ago, was the last day any ink flowed from this shop... dumped that thing & been outsourcing ever since


To the best of my abilities, with spackle, sanding & touch up paint...

So much easier to fabricate for interior installs where it lives in a controlled environment without direct sun and temperature swings.