Thread: Back painting acrylic

Are the problems you are having, with painting in the machined surfaces that you put in, or the original flat shiny surface?

Hi Bob,

It's on the original surface.

What I am doing, is painting the back, then cutting the design with a v bit, and puting paint into the cuts. My plan is to then to glue the piece down into an aluminium form. If the paint doesn't adhere to the acrylic properly, then the final assembly will be suspect.

First clean the plastic surface to remove any grease etc. Paint thinner is good for this.

Next, de-shine it. I would use some 600 grade wet or dry in an orbital sander with water. No need to overdo it but ALL shiny bits must be removed.

Apply paint.

Try a test piece first because although it sounds as though it would ruin the piece it shouldn't do so.

PS You are aware that you can purchase pre painted plastic sheeting. It is used a lot in sign making and for splash backs etc.

Thanks Bob, I'll give that a go.

I haven't heard of the pre-painted plastics...I'll start googling. Thanks.

Look for Zenolite

Thanks Bob

Hey Chris,

I have done a lot of this and find the best results come from spraying a very light coat and letting it fully dry then same same until you have a good coverage, make sure each coat is fully dry first. leave it overnight then machine the next day, if left too long the paint becomes too brittle and you loose the sharpe edges that give such a crisp result. Also use double sided tape to stick it into the recess because liquid glues will reactivate your paint and it'll run and ruin the job . Hope this helps

Any pics of what your doing?

Cheers Gary

Originally Posted by GRS

Hey Chris,

I have done a lot of this and find the best results come from spraying a very light coat and letting it fully dry then same same until you have a good coverage, make sure each coat is fully dry first. leave it overnight then machine the next day, if left too long the paint becomes too brittle and you loose the sharpe edges that give such a crisp result. Also use double sided tape to stick it into the recess because liquid glues will reactivate your paint and it'll run and ruin the job . Hope this helps

Any pics of what your doing?

Cheers Gary

Thanks Gary,

What do you spray it with, hardware rattle cans?

Sorry, no pics yet, I'm only in first stages. I'll post pics when I have something complete, and worthwhile looking at (I hope).

Yes Chris just ordinary spray cans

Hi,

Not sure of exactly what depth of cut you are making, but may be an option for you? and may give a nice professional finish.
Could you fill the machined areas with polyester resin mixed with a coloured pigment. Just a thought.

Cheers
Tony.

Hi Tony

Only need to cut .3mm deep for the colours

see here for some info
https://www.woodworkforums.com/f170/a...perspex-75834/

Cheers Gary

Originally Posted by GRS

Hey Willy , here is a V Carve preview, I think this would be a good one to do not too many colours why dont you give it a try? Obviously V Carve does not allow multiple colours in preview.

Thanks for that info Gary.

And a little bit of info for you, VCarve does allow multiple colours in preview. Maybe it didn't when you wrote that.

Hey Bob ,

good to hear from you , yeah mate that post was back in 08 so obviously things have changed, just trying to pass on the acrylic experience , trial and error is the best teacher

Cheers

gary