Painting 1″ thick letters gatorboard (ultraboard)

[signbrad]

The job looks fine, nolanola.
I am curious which of the Graco True Coat model guns you used.
Has anyone used the cordless?

If anyone is curious, I worked at a shop for about a year back in the 80s that regularly installed large Gatorfoam letters outside, simply gluing them to walls. They generally looked good about two years, though some lasted far longer. They were not intended to be long-term signs. I painted hundreds of them personally, using acrylic enamel automotive paint (catalyzed). I primed edges with latex, usually a triple coat, keeping the faces wiped clean. Painting the backs not only kept them from curling, but permitted a better bond for the silicone used for installing.
I don't have experience using Ultraboard, but I understand that the overlay is a plastic rather than a wood product, so I would expect a binding primer to be necessary for topcoat adhesion.

Brad in Kansas City

 

[nolanola]

We used the corded Graco from home depot ($250.00)
The letters we produced are installed indoor.
I hope the paint won't fall off.
Next time we will use a primer.

 

[Rico]

GLad it turned out okay for you.

A little late for advice but here is how I would (and do) work with gator.

For inside:
find what size sheet you will need for the letters, say 4'x4' piece for instance. prime both sides with 1 coat of chromatic universal white primer. When dry, sand and then coat each side with Ronan Aquacoat lettering enamel. When dry, sand and coat each side with a water-based matte clear of your choice*, I use Miller Paint Acryclear, but they're a local company. Any waterbase clear should work though as long as it has some basic UV inhibitors.

After proper drying time, mask top/face side and cut out letters, either CNC or bandsaw, whatever.

Before peeling faces, paint edges with same Ronan Aquacoat -- no need to prime for indoors -- and peel mask off as you go. if any paint leaks under masks, wipe off with water as you peel. Letters will be finished once the edges are dry.

*matte clear for indoor lettering cuts glare from overhead and/or spot lights and makes for a better looking product in general.

 

[nolanola]

Thank you for the advice.
We are working on the next ultraboard letters project now.
These are 2", and 24" tall.

Is it a good idea to wrap the letters?
Will vinyl stick to the foamy parts?

Thank you.

 

[Rico]

Thank you for the advice.
We are working on the next ultraboard letters project now.
These are 2", and 24" tall.

View attachment 129601

Is it a good idea to wrap the letters?
Will vinyl stick to the foamy parts?

Thank you.

I honesty have never used ultraboard and just read about it, but if you are using the one with the polystyrene face, then I am confident Ronan's aquacoat will stick with no primer needed. I have cut thousands of Sintra letters and use aquacoat exclusively for inside work and it sticks perfectly and covers in one coat (and paints generally don't like to stick to PVC). All I have to do is sand with 320, wipe with tack rag and then wipe with lacquer thinner then paint.

I wouldn't consider wrapping with vinyl. At most, if I was desperate, I would cover the faces with vinyl and paint the edges with the paint above. It is a lettering enamel, so even dark colors cover really well. With very few exceptions, one coat will cover fine, even with foam edges.

you can get it a dick blick online. there are usually email offers of 25% off or free shipping. thin sparingly with isoproyl alcohol

 

[nolanola]

Why wrapping the letters is not a good idea?

 

[Rico]

Why wrapping the letters is not a good idea?

I have never heard of dim letters being wrapped. Seems like a lot of unnecessary work, but I don't know your shops capacity for painting.

A few times I have taken stock vinyl colors and covered a blank sheet, then cut out letters then painted edges and peeled similar to what I described above with the gator. Worked fine. But wrapping edges? Seems very time consuming and how well would the vinyl stick to foam?