Rescuing a 3D project

[kc10flteng]

Howdy guys...I just did my first 3D project - a "Staff of Alcepius" on MDF,(snake twined around a staff) for a military medical outfit, size is 28" x 16" x 2". The piece turned out flawless until I managed to jack it up with a bad paint job. Before I make matter worse, is there a smart way to remove this paint from the carving without damaging it? My first thought is to sandblast it...! Any ideas? Thanks Ron

[rob_bell]

Perhaps this is a crazy suggestion but if you can get the piece back on the bot perfectly registered you can carve it again, maybe a 1/64th deeper.

[harryball]

What kind of paint? You might try a paint stripper.

I've made similar mistakes and on most occasions ended up tossing the original and recutting the item while I was test painting on sample boards. I've now adopted a new policy, I never use unknown paint or technique on the real thing. The "figure it out as you go" policy can be a real PTA when applied to a 6 hour carving.

Robert

[joe]

Ron,

You didn't mention the type of primer or paint you used.

MDF soaks paint deeply unless it's primed. Even then you might re-prime and give the piece another attempt at painting.

[kc10flteng]

Joe - I used a Shellac based primer & enamel paint. It's a combo I've used before....that being said, painting is not my forte. I don't have the time to recut the piece( 12 hours total cut time,besides I managed to run my rough cutter into a hold down screw - it's toast!

[butch]

For carving fish used Acetone. There are lots of small details that need to be cleaned. But there are times it takes 4 or 5 times to get the painting right. I make a tank out of plywood, and line it with plastic bag, fill with Acetone and let the item soak, then wipe off. Pour the Acetone into a pail and let settle and you can use it several times.
Beware - it needs to be ventilated, or do it outside.

[harryball]

Ron... If it were me, I think I'd figure out away to get the cutting process started again to cut the second attempt. I know you said the bit was blown, anywhere to get another bit quickly?

While it was cutting my second attempt I'd then resume my efforts of paint repair which sound like they could take some time. If all else failed you'd have another one to attempt painting in 12 hours.

Robert

[joewino]

Are you planning to repaint the carving or just remove the existing paint and leave it raw?

I guess my main question is, if you plan to repaint it what are you going to do differently this time to make it successful?

You might want to consider getting someone else to do the finish work that is more accomplished at painting than you, and then practice up more for the next job.

[joe]

Since you primed with Shellac, which is a good first step, you may be able to save the job with little effort. Here's what I'd do.

Mix equal parts lacquer thinner and alchohol. Gently scrub on this solution with 0000 steel wool. This should get you down to the shellac primer. Do not soak your piece in this mixture. Gentle rubbing, then re-prime with shellac.

A beautiful finish requires may require some skill you may not have acquired. So you might seek some help with this part of the job.

Would you please post a photo of the project?

[kc10flteng]

OK guys, here is the finished project. I ended up sandblasting it and filling in the unavoidable damage with wood putty the painting it. I had to get good FAST with an airbrush to get this one painted on time - masking was a nightmare. Didn't go so bad for a first go and boy did it pay the bills. A quick plug for James at Carve 3D who expertly handled the artwork. Overall size was 28 inches by 16 inches x 1.75 inches. For the newbs like me, the lesson learned here is once it comes off the bot...it ain't done! Think it through to the end. Thanks for all the suggestions guys.
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[srwtlc]

I once read a saying that "The sign of a good craftsman is not that he makes no mistakes, but that he knows how to fix those mistakes"

Good job!

[jhicks]

Ron, that looks like a nice recovery and crisp paint separation on a complex shape. How did you separate and finish the color coats? Tape mask and spray or some other trick? You are right about projects being quite a lot more than the cutting. Design, preparation for finish and finishing quality is always the detail that makes or breaks a piece so design and finish strategy is critical to efficient assembly and finish.
Let us know how you separated the components for color coats around those edges.
Nice job and I'm sure the client is pleased.

[bleeth]

My version of that line has always been "Anyone can take forever and do a great job; it takes a pro to knock it out in the right time and fix the mistakes before anyone knows they were made."

That's such a nice job-the snake should be smiling.

[kc10flteng]

Jerry, I painted the whole thing white as a first step, then using model airplane masking tape (1/8") wide, separated the snake from the pedestal and staff. Then masked everything that wasn't going to be purple with frisket film and ordinary low tack (blue) masking tape. Same process to mask & paint the staff. I used an airbrush (Iwata Eclipse) with thinned down enamel to paint the snake & staff. With a bit of practise one can draw a pretty good thin line and do the detail work required for a piece like this... but for big money work, this is a chore best left to those skilled in this art. I gotta tell you I got a sharp lesson in just how much effort goes into getting some of this 3D stuff prepped and painted. Next to that spindle on the bot, that little airbrush is some of the best money I've spent so far on this CNC venture. Bottom line is the customer liked it - a lot - & it got more biz for the bot - "finish matters" if you will. Here's what the rest of it looks like - all done on the bot. Size is about 80 x 66 inches.
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