Finishing HDU

[abadsvt]

Hi Guys, Not sure if this is the spot to post this in but I am building an HDU sign for a customer. I designed it then took it down to a wood working shop and had them CNC router it. It came out beautiful. So now since this is my first HDU sign i was curious on finishing it. I read tons of threads but noticed that I didn't see anything about home depot latex paint. The customer wants to pick out the colors and thought for convence on getting materials and colors that the new line of Baer primer paint would be a good choice but wanted to hear from the experts! I read that 1-shots primer is the best but wasn't sure if there was any other good primers that might be ready available at the depot. Home depot is just 1/4 mile from my shop. That is the reason for using them plus easy for the customers to be responsible for the color picking. Thanks and will take pics after the sign is all done!

Josh

 

[Patrick46]

Whenever I use HDU, I always lean toward good old house latex paint. Works wonderfully!

 

[abadsvt]

Whenever I use HDU, I always lean toward good old house latex paint. Works wonderfully!

Thats what i thinking also. I just read about "SIGNPRIME" primer and sounds nice. It is pretty expensive though but being able to sand the primer sound like a good thing. You ever use house hold latex primers? Thanks

 

[G-Artist]

We get at least a 1/2 dozen sign and industry trade mags here and I have been reading about HDU since it came out. Never used it myself.

All, to a one, stated that it is best to use the recommended primer and use it as prescribed in the literature. Then you can use any paint you wish as a topcoat.

 

[Mainframe]

Sherwin Williams super paint, also they have a great primer, can't beat it, use foam brushes

 

[petrosgraphics]

we use a lot of HDU, over the years....before you get started priming, make sure you
sand the surface with 220 grit sandpaper get rid of as many scratches,scrapes, etc.
as you can find... we use ben moore fresh start latex primer, found this to work real good.
i am sure any good latex primer would work, we have stuck with the fresh start for it works for us.... if you put 4 coats of primer sand each coat with 220 paper you should be ok... as for your finish coat, oil or latex does not really matter

 

[Salmoneye]

I like to use oil base for anything that I want to last. I would not use any paint from a box store like Home Depot. Even if it is the same brand as they sell in their professional paint stores it will almost certainly be a different formula with less solids etc... When I used to buy tons of Glidden, the cheapest paint in the pro store was better than the top of the line in the box store.
2 cents

 

[JK driver]

We use automotive primer and paints. We spray the panel with a good high fill automotive primer sand with a DA. Also make sure to prime the back to avoid warping. This is caused by primer/paint shrinking during the curing process. Priming the back will counteract this. Fill any pin holes left. Paint with a good gloss automotive paint. Then Gerber mask the panel rout it then prime and paint the copy. Peal the mask and it is done. This will last a long time!

The analogy I use is: How often do you paint your house? And how often do you paint your car???

 

[abadsvt]

Thanks guys for the help and knowledge. I thought it might be benificial to see the size fo the products that i am doing. The small address sign is aprox 15" x 25" and the larger sign is a 24" x 36". Also i added a pic of whats getting painted on the larger side so you can invision what i am doing. If you look at the larger HDU sign i have going you'll notice that on the right side in the middle is a saw cut that isn't suposed to be there. What would you guys recommend on filling that saw cut? THanks again everyone!

 

[k.a.s.]

As was said, sand first try and get it as smooth as possible. We use Signprime, it works well and you can sand it smooth in between coats. It is pretty hard to get a nice smooth backround surface when you are hand painting around all those letters. I usally use a solid color stain on the backround, I like the contrast of that vs the high gloss on the letters. I finish with Ronan paints, we mix a color if we have to match somthing. One Shot has a lot of colors that you can use as well.

Kevin

 

[Mosh]

about home depot latex paint

That would be like restoring a classic car and then spray painting it with krylon.
Use a good paint and primer like Ronan, something made for a long life. That crap HD sells is for DIY people who don't know what they are doing anyway, so won't know a quality paint.

 

[signmeup]

That would be like restoring a classic car and then spray painting it with krylon.
Use a good paint and primer like Ronan, something made for a long life. That crap HD sells is for DIY people who don't know what they are doing anyway, so won't know a quality paint.

Baloney. I use Home Hardware 1080 latex primer. You don't have HH down there so go to a good paint shop and ask for something to prime plastic house siding that is sandable. Wash the sign with a garden hose before you prime it. Blowing it off with air won't get the dust out of the "pores".
I use a brush to prime the panel (2 coats) sand it between coats with 320 grit. (A roller won't get the paint into the "pores".) Then use foam rollers for the top coats, again latex house paint. Pittsburg Sunproof is good. It drys without tac which is real nice when you want to gild the lettering and not the whole sign. BTW....carving and painting through a mask will save you a ton of time....next time.

 

[Just Another Sign Guy]

there are quite a few signmakers who DO NOT prime hdu at all...and before you say it, no they are not hacks. if you are using a low poundage then you will probably need to prime to fill the holes but the heavier stuff some people only prime to achieve light textures by crumpling a brush for small peaks and valleys or a rough roller for light bumps.

here is some technical data http://www.signfoam.com/tech.php?mode=finishing

myself i avoid high build primers like the plague invest in higher pound sheets and save yourself a tremendous amount of finishing labor.

 

[abadsvt]

there are quite a few signmakers who DO NOT prime hdu at all...and before you say it, no they are not hacks. if you are using a low poundage then you will probably need to prime to fill the holes but the heavier stuff some people only prime to achieve light textures by crumpling a brush for small peaks and valleys or a rough roller for light bumps.

here is some technical data http://www.signfoam.com/tech.php?mode=finishing

myself i avoid high build primers like the plague invest in higher pound sheets and save yourself a tremendous amount of finishing labor.

That is a good point. Both signs are 15lb foam. When you mention higher pound foam are you refering to 20lb and up? Thanks

Josh

 

[abadsvt]

That would be like restoring a classic car and then spray painting it with krylon.
Use a good paint and primer like Ronan, something made for a long life. That crap HD sells is for DIY people who don't know what they are doing anyway, so won't know a quality paint.

I am a classic car buff so thanks for putting it that into my language!

Josh

 

[abadsvt]

Baloney. I use Home Hardware 1080 latex primer. You don't have HH down there so go to a good paint shop and ask for something to prime plastic house siding that is sandable. Wash the sign with a garden hose before you prime it. Blowing it off with air won't get the dust out of the "pores".
I use a brush to prime the panel (2 coats) sand it between coats with 320 grit. (A roller won't get the paint into the "pores".) Then use foam rollers for the top coats, again latex house paint. Pittsburg Sunproof is good. It drys without tac which is real nice when you want to gild the lettering and not the whole sign. BTW....carving and painting through a mask will save you a ton of time....next time.

Thats a good idea. I will call the local paint store (not home depot). Thanks for the help!

Josh

 

[Just Another Sign Guy]

yes higher density like 20# and i understand that it can be hard to obtain if you do not have a distributor that can justify stocking a large selection of sheet thicknesses and a variety of densities because they will usually default to the lower densities because they are cheaper per sheet.

there are a few brands out there as well signfoam, duna, etc. duna used to be very generous in providing a nice box of samples approx 1' X 2' in a variety of densities. i would highly recommend requesting them so that you can experiment without having to buy a sheet.

 

[diverscott]

Another thought on "justifying" going with the higher poundage:

"The money you save on materials, you'll spend on labor getting it right."

We use 20# and spray auto primer and paint (with hardener).

 

[NY Signman]

MOST IMPORTANT FIRST STEP..................... BLOW THE HDU OFF REALLY WELL! Run your hand over surface while using air gun.....bleed off any water in line prior also.

Can't tell you how many times over the 15yrs using, that while you peel off mask after gold leafing, something lifts back to the bare HDU. When you think it's blown off enough, go over it again. Haven't had a problem in over 5yrs.

Fresh Start, 2-3 coats, then into whatever finish you wish......I've brushed Chromatic, One-Shot, Latex, have also sprayed and rolled....all the mentioned.

The HDU of today...........soooooo much tighter cells and smoother then the orig. precision board we started with!

GREAT STUFF!!! Always recommend it to my customers for ANY high end sign....especially w/gold leaf.

Good luck

 

[signmeup]

I have found that blowing the dust off is not good enough. That dust sticks like it was designed to.

I recommend blasting it with a garden hose. The only thing I've seen about useing auto primer on HDU from a manufacturer was they didn't recommend it. Why? Who knows. It worked fine for me. I just don't like useing it. Latex primer for plastic house siding worked fine for me and the brand I use sands great.