HDU finishing

[john_hartman]

Hi guys- I'm taking on my first project which will be exclusively made from .75" & 1.5" HDU. Some of the parts will need to be finished in 2, 3 or 4 different colors. I see some of these signs you guys are making and notice how crisp the seems are between two transitioning colors. How is this done and what are the best primers, paints, and masking materials to use. Does anyone know of online step-by-step instructions?

Many thanks...

[kartracer63]

I'm very interested in this subject as well.

Thanks from me too...

[joewino]

This question comes up lots around here lately.

First of all, HDU does not need a primer - almost anything will stick to it, but a primer just helps to give a smooth finish.

We try to cut the HDU in layers so that they can be painted and then assembled rather than trying to paint two colors up to each other.

After years and years we have found Porter 100% acrylics to be the best application for our area. We spray on a coat of Coastal Enterprises filler-primer (FSC 88-WB) with a HVLP gun made for latex paints and then spray a coat of the Porter background color. Smaller panels, trim, etc. are brushed with a small brush made for latex paints.

Usually two coats are required but we may do three just for better coverage and to combat fading.

There may be some You Tube instructions, but I don't know of any.

[john_hartman]

Raymond, thanks for the reply.

I will be using either 10 or 15lbs .75" & 1.5" precision board. (Experimenting today to determine which one to use) I have read that primer is not mandatory however I can't see a way around not using it to smooth out the milled areas. I have a sample of this FSC88. How much are you thinning it to spray well? As thick as it is I'm wondering, after thinning, if it will just get back to the viscosity of standard primer like Zinsser? Also, the FSC88 video says that it needs a lot of air movement to dry, then more air an hour prior to paint spraying. Is it really that problematic that it will cause blisters if the once cured primer has a small window to re-absorb moisture in the air?
Also, does the back really need to finished as well? The finished parts will be attached directly to drywall.

I will be cutting many parts in layers and finishing separately, however I have a few parts which will be v-carved and have shallow pockets. I see that it is possible to spray the first primary color on then use a roller to apply the secondary color creating the desired color separation. While this could work I this project will be indoors and visible from two inches away. So I need it to be tight. This is my biggest area of concern.

[joewino]

You would need to paint the back with the same number of coats as the front to prevent warpage, but if it is inside they may not be a problem.

The FSC 88 has to be thinned a lot to get it to go through a HVLP but you can spray on several coats to build it up because it dries so quickly (at least here in Texas it does). I've not used Zinsser so I can't give a reliable comparison, but the FSC 88 is more than just a primer - it builds up a layer that becomes super smooth when it is sanded.

Rollers never have produced a really smooth finish for me, and trying to roll across a V-carved area just doesn't give a sharp enough edge for me, but that's just my opinion.

[john_hartman]

I will experiment with the two primers; super smooth is the desired result.

What is the best way to attach HDU to drywall that is invisable? Is there a quick set glue which will do the job? Some of these parts will be 4ft in diameter.

What application method do you use for 2-color v-carved areas to achieve sharp edges?

[toych]

You may want to have a read through this book. It mainly deals with sandblasting but also has a good section on finishing Sign Foam.

Mastering the Art of Dimensional Signmaking.
Michael Bloomquist
ISBN: 0967252903

[joewino]

John - I had posted another answer to your questions back before Christmas, but it must have been lost in cyberspace.

To get a sharp edge on our V-carve lettering we just use a sharp brush. I just don't like the edge produced by rolling. It's time consuming but the result is what we want.

For installation we drill holes in the back of the HDU and set in threaded rod using epoxy. Then a pattern is made of the bolt pattern to be transfered to the wall. Drill holes in the wall and fill with silicone sealer (clear) and then just push the sign into place. Friction will hold everything in place until the silicone sets up.

Normally we also back our HDU with aluminum or Dibond.

[john_hartman]

Raymond-

"To get a sharp edge on our V-carve lettering we just use a sharp brush. I just don't like the edge produced by rolling. It's time consuming but the result is what we want."

Does mean your painting by hand and not spraying? So you would paint the v-carved letters one color then go back with a hand held brush to apply the second color.?

[chiloquinruss]

Not for v carving but for other signs I use a vinyl cutout as a mask. Before applying the next color and peeling the mask, I spray on a very thin coat of clear over the mask. This seals the edge and does not allow the second color to 'bleed' under the mask. I let the clear dry just a little and then apply the next color. I also used this same method on stacked vinyl stencils. I've not had very good luck doing v carving with vinyl, but many here have. The best v carve I've done was cut into a prefinished panel, I then v carved and then painted. While the v carve paint was still 'wet' I cleaned up the edges. A lot of work but looked good enough for the customer. Russ

[dakers]

V-Grooved Signs A refined sign with an elegant look, v grooved signs have a timeless look. Carved from a solid piece of HDU we first prime and paint the substrate, then cover the face of the sign blank with Oracal paint mask. Next, we secure the blank to the surface of our Shopbot router. Using a v shaped bit the cnc table carves the text and graphics into the face of the sign. After priming and painting the v-carved areas the mask is removed leaving and crisp, clean paint line between the carved letter and the sign face.

the above was copied and pasted from
http://www.blueridgefabrication.com/cncroutedsigns.htm

we do it both ways. as a signpainter it is easy for me to just paint in the letters. we have also used mask but we used only matthews acrylic two component polyurethane paints as we had their mixing station. most of what we did was gloss and the paint was hard so the mask worked perfect. i have used xim clear primer on mask before to prime the routed parts and seal the mask so the paint did not slip under. No one way is perfect but everyone finds a way that suits them. I probably chose the method based on how many letters are carved and what size they are. I do not like to hand paint alot of small v carved letters.

[dvmike]

The technique you use in painting depends a lot on the format of the sign....or at least that's my experience.
If I'm using HDU I usually paint with either one shot , or Lowes severe weather. Yep ! It works great !
Most of my signs are raised letter with a framed border . I spray the entire sign with the color to be used on the background and then use foam brushes to paint raised areas and letters.

[joe]

Mike,

Please post photo of the foam brush technique!

[benchmench]

Ditto on the foam brush technique. I've used a small foam roller on raised letters that are flat on top but beveled 3D raised letters have required hand painting with a brush.

[joe]

Me too Dan,

I hand letter a considerable number of signs. I've never been able to do much of anything with a foam brush. That's because they lay down a very thin coat.

I seldom, if ever, post on a topic without a photo as an example. Pictures aren't used enough on this forum. Words are a poor substitute.

[ghostcreek]

I don't know Mike Chappell's technique, but I have used foam brushes for raised carving area's. I just cut the foam to a size that fits the area to be painted, and on i go. For me, it has eliminated my stray brush marks. just my two cents.

[joe]

Michael,

There shouldn't be any brush marks. Perhaps you should consider changing the type of brush

Lettering artists, around the world, have been stroking paints since Ancient Egypt.

Mac Brushes now sells lettering flat and quills specifically for latex. The advantage of a good brush is, it loads up with plenty of paint and lays it down smooth as glass.

[joewino]

Like Joe said, good brushes are much easier to use and do a better job than foam brushes. I've never been able to achieve anything like a brush applied film with a foam brush - at least not for small areas.

[joe]

Raymond,

Us seasoned sign artist, enjoy working with our hands. Like you I enjoy carving, sanding and painting as well as routing. A machines can get you a ways down the path, but at some point you have to get your hands dirty. That's where skill comes into play.

Brushes are friends. I have some aging old quills reaching back two decades. Their my trusty old companions not to mention the hand-me-down chisels from another generation. Those old boys are kept razor sharp ready for action. The digital age has seperated us out. It feels good knowing your craft and having clients seeking the services.

I'd encourage every aspiring sign artist to find someone they admire in the craft and follow their lead.


Look forward to seeing you this Friday for steaks and good conversation.

[ghostcreek]

My tip for foam brushes was only for the raised sides of lettering, only something that worked for me. Being a disabled vet, I have to find work arounds for certain tasks. Only offered my work around. I get my hand very dirty, as i am sure the ancient egyptians that had challenges did likewise.
Example, try washing one hand sometime!

[joe]

Michael,

You'd be amazed how nice a good brush would work for you. It's you're call however. All of us have to find our way.

[joe]

I get a great amount of inspiration from one of the local guys Greg Burns. He's now making his way on the national scene.

http://www.gregburns-fineart.com/originals.asp

[rej]

i will be posting pics of the painted hdu soon.
i ended up going to a body shop and having them painted.
they came out perfect.
the cost for priming and painting was 15.00 per sign blank 37x9 inches each. total of 60 pieces
they look like the finsh of a brand new car.
i mask them with oracal 813.

once the letters are carved, paint the letters.
then i take 220 sandpaper and sand the rims around the letters just till i see the the mask.
then i peel the mask off.
i will post pics of the entire process in the next week.

[dvmike]

I bought a realitively inexpensive 1 quart paint sprayer for big jobs and a 1 cup sprayer for smaller jobs.
I paint the entire sign with the sprayer to get a smooth background finish. I usually do about 4 coats and dry between coats with heat lamps.
Then I paint all raised areas with a 1" foam brush.Recessed areas can be painted with foam brushes or an artist brush depending on application. (Most of my signs are raised letter.)
After I finish painting , I use 2-3 coats of clear polyerathane (spray can) to weather proof and give the finish a sheen.
On most of my signs I use Lowes severe weather paints because its easier to use, less expensive , and more versatile. The polyerathane gives it a shell to fight fading and weather.
6002
6003

[rej]

mike,
a. how long have your signs been out there in the weather with this method?
b. this sign looks like you textured it on the bot , did you pocket cut it first?
c. looks like you applied the border, did you?
d. looks like you still have a pebble grain finish. do most customers say that is fine enough?
thanks

[joe]

Excellent job Mike,

Thanks for posting the fine examples of sandblasting HDU.