Growing a pattern with paint

Pattern making is an art, either by machine or traditional it is the key to success in casting.
User avatar
Jelly
Posts: 55
Joined: Mon Jun 06, 2011 12:51 am

Re: Growing a pattern with paint

Post by Jelly »

Harry, this is right up my alley. Any Ultra high solids 2 part epoxy based paint can be put on as thick as you want as long as you mix the paint properly. The US navy uses this on thier ships, It can be sprayed, brushed, rolled.... You can go to just about any sherman williams or similar store, and ask for 2 part epoxy high build paint, if you start throwing names like 150 mare island green, or 151 Haze Gray, they'd be stupid if they didnt know what you were trying to get. If you chose to roll this stuff, make sure the paint supplier gives you some Wet film thickness guages and ensure that your wft's corelate to your percentage of solvents. IE, 12 wet mils will get you 6 if its 50 percent solvent. Its a FAST way to build millage. :) (I know, we've screwed up a few times and put 40 mils of this stuff down in one spraying, sanding cured epoxy paint is NOT fun)
User avatar
Nudge
Posts: 305
Joined: Sun Jun 05, 2011 6:18 pm
Location: Auckland, New Zealand

Re: Growing a pattern with paint

Post by Nudge »

(sanding cured epoxy paint is NOT fun) only if you leave it for too long, I have been using one thet is easy to sand... but only if it is done in the window of 12 to 72 hours any time after that and it IS a sod.
I like to build "Stuff" using Stuff that costs Stuff All!
castaway
Posts: 22
Joined: Sun May 29, 2011 7:08 pm

Re: Growing a pattern with paint

Post by castaway »

I have never tried this but one caster said he dipped his patterns in wax or paraffin to get a build up on surfaces. They also sell sheet wax in different thickness to build up surfaces to the needed heights required.

I do used Bondo or Poly Putty but that's extra work shaping it after. Another method I use is duct tape or masking tape to build up a surface where it is feasible to do so. 8-) Poly Putty is softer then Bondo and will sand better.

I do used bee's and investment waxes that I heat up with a heat gun to a soft molding state and press it in low areas to get the correct draft to keep from getting sand pulls. This is usually done to a pattern that is on loan and needs to be returned as received otherwise I would have probably gone with Bondo. :roll:
Image

I used to spend my time to save money but now I'm willing to spend my money to save time.
User avatar
4cylndrfury
Posts: 140
Joined: Thu Jun 02, 2011 10:09 am
Location: Cincinnati, Ohio, USA

Re: Growing a pattern with paint

Post by 4cylndrfury »

When I needed to add draft to the MAF pattern I made, I added a 1/4" wide strip of masking tape around the base of the cylinder portion, about 3 wraps. This widened the base about 2 mm. I applied drywall mud with a putty knife to create draft between the now wider base and the now narrower top. Worked well, now there are no issues with sand pulling when I remove the pattern. Im thinking I might add draft to the inside the same way and then I can avoid the core issue with this patter. It may require a return to the drawing board, but this pattern has been so molested, at this point a fresh start is worth it lol

-Drew
Last edited by 4cylndrfury on Wed Jun 08, 2011 9:49 am, edited 1 time in total.
"Simplicity is the ultimate sophistication"
-Leonardo Di Vinci

"The future's uncertain and the end is always near...."
-Jim Morrison
User avatar
Harry
Site Admin
Posts: 1020
Joined: Fri Apr 16, 2010 10:15 am
Location: Onyx California
Contact:

Re: Growing a pattern with paint

Post by Harry »

Well I have been working on this pattern over the last several days getting at least one and some days two and three coats on it each day. Have been letting it cure on out the last two days and will likely give it a try today or tomorrow to see if the parts come out sized right now. It would have been a lot quicker to simply cut a new pattern scaled up but I already had this plate made up with 4 of these parts on it so the easy route was to paint it, we will see how it did when I do another casting run.
I'd rather laugh with the sinners than cry with the saints the sinners are much more fun...
Muller
Wayne
Posts: 28
Joined: Tue May 31, 2011 10:27 pm
Location: Charlotte, NC

Re: Growing a pattern with paint

Post by Wayne »

How did that come out Harry?

Found this while looking for something else, http://www.paintforcars.com/primers.html

Wayne
User avatar
Harry
Site Admin
Posts: 1020
Joined: Fri Apr 16, 2010 10:15 am
Location: Onyx California
Contact:

Re: Growing a pattern with paint

Post by Harry »

Came out a perfect fit Wayne, the part was a little loose in the part it fits into and after half a dozen coats of paint it now fits like a glove. That automotive high build would probably be a lot tougher and last longer on the pattern but the Rustoleum rattle can is so easy to use.
I'd rather laugh with the sinners than cry with the saints the sinners are much more fun...
Muller
Wayne
Posts: 28
Joined: Tue May 31, 2011 10:27 pm
Location: Charlotte, NC

Re: Growing a pattern with paint

Post by Wayne »

Harry wrote:Came out a perfect fit Wayne, the part was a little loose in the part it fits into and after half a dozen coats of paint it now fits like a glove. That automotive high build would probably be a lot tougher and last longer on the pattern but the Rustoleum rattle can is so easy to use.
Good to know about the rusto..

Wayne
Post Reply