What kind of foam to use?

[jackarnoldhurley]

I need to machine some 3d letters (2" thick and about 12" tall) that will be painted and glued to some sort of hard board for a theatrical production. I'm wondering whether 2" insulating foam board from Home Depot will work or whether I should be ordering something more exotic. Can anyone help me out?

[steve_g]

Get the HD stuff! Use it for props all the time!
SG

[jackarnoldhurley]

Do you mean the high density foam sold in sheets and used for seating/mattresses etc? I didn't realize it was stiff enough to be machined.

[joe]

I think what Steve's talking about is the blue or pink styrene.

Yes it can be carved, a little, but your description of "3D Machine" is so vague no one could advise. Could you please post a photo or something to go on? This forum is a great source of information but you gotta be more specific in order to get it to work.

Joe

[steve_g]

Yes, as Joe speculated, I was assuming styrene insulation foam that you would get at a building..g supply. I’ll attach some images of styrene foam props I’ve done… If you look closely you’ll see some V-carving I did on the carriage.
I have done some cutting of flexible polyester foam for case linings. I don’t recommend it! Basically it was controlled ripping out of chunks.
SG

[jackarnoldhurley]

Thanks, Steve! That's what I needed to know.

[David Iannone]

Steve, those look good. For some reason I have never played with the pink foam from HD. I always used to read on here how its good for practice cutting, and things like you show in your pics.

Do you think.......just maybe......If I was to say cut a 2' tall letter, then spray it with Rustoleum Leak seal and cover all the pink with the rubber coat.....then maybe it could last outside?

I suppose a trip to Home Depot is in order for a sheet of the pink cause I just got to try it just to see if the spray will eat the foam. I am probably headed down the wrong road here I know.

Dave

[steve_g]

Dave…
I see temporary Styrene lettering all the time around here. I’ts very susceptible to vandalism and UV. If you can keep it protected from UV and mechanical damage I think it might last 5 years…
SG

[jerry_stanek]

We installed many of those style letters in CVS stores

[steve_g]

Jerry…
Outside?

[David Iannone]

Ok then, I will get a sheet, cut some stuff and spray it and report my findings back with pics.

[jerry_stanek]

No inside. Remember to use water based paint or you will have a gooy mess

[mikeacg]

The whole front of my shop is made out of blue foam and has survived several hard winters here with no problems... I primed it and painted it with exterior latex.

[joe]

There's a history about these materials on this forum.

You know what makes a sign cost so much? It's the rent, utilities, bills, insurance, truck payment, and everything that makes a business run. Materials costs are a small part. Why not use the best you can get.

Here are some we made for the County Election Board. Why pay Peachtree when you can do it yourself.

[kurt_rose]

Very nice Joe. Did you just use a stucco coating over the foam or something more exotic?

[David Iannone]

Michael,
Those look great!

Joe,
I am so full of all the things I want to try, and ideas of what I am going to accomplish this year. You are correct, I should have searched, just thought I would jump into the mix with the quick question.

I guess if I had just thought about what I was asking before I did it, I should have known if Peachtree can use cheap foam, so can anyone. (with the proper techniques of course) I remember seeing that sign you show in the post you made with it a while back. But didn't remember it till you re posted the pic. Thank you. The pic most often help me understand better, but now I have to experiment. And experiment I will do.

I agree, I am not about trying to find the customer a "cheaper" way anymore. I am just wanting to learn how to be more creative. Use my strong points, and sub out the stuff that I am not good at.

By the way, I have struck a deal with the guy a few stores down from me to do a vehicle wrap for him and him build me a website. I am excited. He is doing all the design of his wrap by the way, as you know I admit I am NOT a designer. Hopefully this goes well. If it does I will be having him design the wrap for my truck that I will print and install myself. (one of my strong points)

Sometimes I think you just have to sit down and figure out "what the heck am I the best at, and enjoy the most" and try to head in that direction.

Dave

[joe]

Kurt,

I'm liking your work. Your showing lots of creativity and look forward to seeing what your up to in the future. You've got the right stuff!

Hardening off EPS:
That's a real trick. I've tried about everything with little success and lots of failures. The best thing I've found is to use the cheap foam for the center of the sign having the first surfaces from MDO or Extira. The spray I used was exterior sand stucco applied with a hopper gun.

I've not seen many foam signs I'd want to put my name on.

Joe

[dan_nelson]

Whats the best kind of adhesive for laminating blue foam together?

[steve_g]

Dan…
I’m not sure what the “best” adhesive is… here’s what I’ve used. To build up structural shapes like in the attached stable, I use the foaming gorilla type glue. Because this glue expands as it cures, it can be a problem when building up large pieces… The glue expands with such force it’s hard to control! To laminate sheets, I’ve used 3M 77 spray adhesive… keep in mind that my projects typically don’t need to last a long time, so I don’t know what the long term results are!
SG

[kenkelsey]

Dan…
I’m not sure what the “best” adhesive is… here’s what I’ve used. To build up structural shapes like in the attached stable, I use the foaming gorilla type glue. Because this glue expands as it cures, it can be a problem when building up large pieces… The glue expands with such force it’s hard to control! To laminate sheets, I’ve used 3M 77 spray adhesive… keep in mind that my projects typically don’t need to last a long time, so I don’t know what the long term results are!
SG

I use West System 2 part marine epoxy, but I use HDU much more than foam. Its not coming apart, that's for sure. Tried the Gorilla glue and it does bond well, but the foaming is out of control. Won't use it again. Ken

[mikeacg]

Loctite PL-300. It's called Foamboard Construction Adhesive. Comes in a 10 oz. tube for a caulking gun. Works great!

Mike

[kenkelsey]

Hi Joe. I am intrigued with your construction of foam signs. We buy several of the style sign from Creative Foam in Georgia, but never considered building it from scratch. Do I understand you correctly that you use 3 inch construction foam for the core and then bond on the front and back faces with MDO or Exteria and then apply exterior stucco? What about the top curved surfaces? Do these signs hold up well. Looking at your pics I would guess the Peachtree price to be about $2,000. I'm sure you have a lot of labor in this, but the material looks to be about $300. I really want to give this a try, but I don't want to supply something that is going to give me problems in the future.

[dan_nelson]

Thanks to all that have replied to my question. Im also looking forward to the reply on kenkelsey's post thanks Dan and Bridget Nelson

[David Iannone]

Here is Joe's original post on that sign, I totally forgot about his post on this from 2010 until he posted the pic and it jogged my memory.

http://www.talkshopbot.com/forum/showthread.php?10552-EPS-Foam-Signs-for-Clevaland-County&highlight=Foam+monument+signs


Thanks Joe, super job and detailed info.

On my ever growing "to do list" is now to try this method by making maybe a 2'x3' sample for my sales area, and could also have a handle on top to take to a customer sales call if needed.

Dave

[joe]

When I was first acquainted with the foam sign business it was something that had to be tried. Over the years we've made several of these. Our latest fabrication, as I mentioned earlier, was to use the foam for the interior structure only. By using Extira or MDO for the exterior surfaces I gained several advantages. The first was a superior hard surface. The second advantage was to apply my letters and logo's with excellent detail and sharpness which the big foam manufacturers loose. For my kind of work detail is essential. Another concern was having to rely on adhesive to hold the hole thing together. I did have one major failure when a monument sign decide to come apart. From that time I used .75 MDO on the front and back that allowed me to use screws through the sign, front and back to hold it all together. Once again, I'm not a fan of EPS.http://www.talkshopbot.com/forum/attachment.php?attachmentid=24195&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=24196&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=24197&stc=1

I've given up on this kind of sign manufacturing and gone to PVC. I've posted the techniques earlier and don't want to boar you with them again. For years I used HDU and before that I was a Redwood guy. Here in Oklahoma it will outlast HDU several times over, due to hail, and is lots of fun to work with. Looks better too.

With PVC you can build as much depth into them as needed by using scraps on the sides, top, and bottom. They're tough as a boot.

Joe

[kenkelsey]

Joe: Beautiful signs. You say you have given up on this type manufacture. What do you mean? You no longer use MdO or Extera for the sides and top or you no longer use foam? I think you are saying that you are using PVC for all of the faces and have given up on MDO or Extera, corrrect? Also, how to you handle the curved surfaces on the top side of the sign? Last question what is EPS (Epoxy)?

[steve_g]

EPS… Expanded Polystyrene. Often incorrectly specified for extruded styrene. Another name for EPS is “bead board”, it’s the white stuff that falls apart easily. Its manufactured by steaming solvent laden styrene beads in a mold.
The pink and blue (and sometimes yellow) insulation board is extruded styrene.
SG

[joe]

For the last year or two I use PVC, Redwood and Cedar. The use of any foam products are no longer used.

Joe Crumey
www.normansignco.com (http://www.normansignco.com)