I made a couple of acrylic signs from 3mm cast acrylic. Black and White material. I am using MinWax polyacrylic to seal the acrylic paint.
Using a rattle can I got a lot of bumps.
Using a normal can and a foam brush, I am getting streaks, more like texture from the brush strokes. I had some bubbles, but multiple passes with the brush seemed to remove most of them.
Any words of wisdom ?
It’s not bad, just annoying.
Bubbles, to me, would indicate an uneven cure due to thickness or something on the surface not letting it bond. And I don’t know what you can use to clean before applying that will not ruin the bond process. Maybe alcohol or MEK?
Good Luck
I cleaned the surface with rubbing alcohol.
After thinking about it, I am guessing that I need to thin the acrylic, so it lays down.
I Painted a lot of coroplast years ago and before Fusion spray paint came along I also tried wiping the material down with rubbing alcohol and that seemed to make it worse. It was most likely cleaning the surface and the clean surface created more surface tension which caused the extra bubbling and strokes. I also tried a propane torch and moved it quickly over the surface to break the surface tension this seemed to work and have a better outcome. I had very good results with the Fusion Spray.
I would be very cautious using the propane torch it may do more damage that good on the acrylic I have only used the torch to make the edges polished.
Fusion for plastic by Krylon should have a clear finish that may work better than anything else.
Anthony
On the current sign I am going to try a second coat of water thinned Minwax PolyAcrylic.
It seems that 10% by volume is max, so that’s tomorrows task.
I was not shy about the amount of material is used.
The sign is 20.5 x 11.75.
I noticed the product dries quickly as I was re-brushing in attempt to limit the bubbles.
It tacked up before it could flow flat, hence the thinning attempt.
I will try the Krylon tactic on the next victim.
I tried diluting the poly acrylic with distilled water. Eye balled a 10% water volume.
I sanded the first layer with 220 using a palm sander to take out the high spots. I had tried hand sanding 320 but that would have taken too long.
Liberally applied mixture. This was much easier to spread and remove bubble. I had a little more time.
The result is cloudy, but the texture is not too bad.
I am about to toss this one, but tomorrow I will try a buffing wheel, just for the experiment.
I tried 600 wet sanding. The debris is in the engraving, paint lost it’s luster.
I sanded the sealant off in spots.
Pulled out a new sheet and making another one.
Bought Krylon clear gloss for a sealant.
With acrylic you should do everything from behind the material. This includes engraving and painting.
DO NOT forget to flip all graphics and text
STEPS:
That makes a lot of sense. Thanks.
Do you put a clear coat over acrylic paint ?
When painting RC car bodies, which are painted on the inside of the clear lexan body, I’ll spray a final coat of white paint to make the colors “pop”.
That makes sense. I am painting a sign on opaque black acrylic.
Would you seal the front side ?
I maybe over doing/thinking this … again
In your case, I would put a coat of clear to seal it.
Ok, What material would you use ?
I have not had luck with Minwax polyacrylic, streaks, bubbles … too thick.
Going to try Krlyon colormaxx clear gloss.
Suggestions ?
James,
I see now you are using Black acrylic. My thought is to use clear acrylic, paint it black on the backside and proceed from there. Sealing acrylic is unpredictable, versus keeping the front shiny surface pristine.
It looks awesome before sealing.
Thanks for the comment that it is unpredictable to seal black acrylic.
If I do not seal it, I assume it will be susceptible to weather, but if inside it might last …
Yes / No ?
Acrylic is pretty durable. “outside” is a broad range of possibilities. From what I’m reading about your goals for the look of the finished product, working from the back of clear acrylic with paint and machining is the way to go. This should provide the most attractive look and the most durability.
The RC Car body is a good shout out by @Steve.Mc . I’ve painted a few hundred of those in my life. Watching videos of that process will inform your understanding of the color applications and some masking techniques you might find helpful for more complex designs.
For this effort, I think I will skip the sealant. 3rd pass, I have had enough.
I will try it on some scrap that I have accumulated.
I never considered using clear and going through your process.
Hmmm …
Another advantage of going clear is that you’re not constrained to one background color. And if you plan it out, no masking is required. The spartan logo was carved on the backside, sprayed white, and then I sanded the back an sprayed the green.
The H&H logo, I cut the blue areas first, sprayed the blue, and then cut the red areas out, and sprayed them. Followed up with sanding the back, and spraying silver metallic, and backed it with black lacuqer.
Outstanding examples @Steve.Mc, love it.
I am not is this league yet … WOW !!!
