FDM Prototype Smoothing

Xyborg · 09-06-2010, 04:48 PM

I had some prototype Weighted Companion Cubes made with an FDM machine out of ABS plastic. One prototype is about 4" on a side, the other measures a little less than 1 inch on a side.

I'd like to make molds to produce some resin or plaster copies, but I've never done this before.

There's a bit of surface roughness that I'd like to smooth out. The only time I've done this in the past was with some Squadron green putty, which seemed to bond to the ABS plastic acceptably.

Is there a better way to do this? I'm almost tempted to spray it with some crack-filling aerosol primer paint, but I don't know if this might mess it up or otherwise make the pieces unsuitable for mold making.

Does anyone have any suggestions for how to do this?

modelnutz · 09-06-2010, 06:43 PM

I do SLA benchwork for Fisher-Price and the fastest way that I've found is to spray the part with a good Lacquer based primer and then smear Acrylic Red Spot Filler putty all over the part...being sure to press the putty in to the depressions well. Let the putty dry for 12 to 24 hours...sand...prime...re-apply putty as required....sand....prime...repeat as required.

Once you have a good smooth primer surface...I usually sand with 320 grit or higher for a very smooth plastic surface.

Takes about 1/3 the time as sanding the raw part.

Xyborg · 09-09-2010, 11:48 AM

Thanks for the detailed reply! I'll give it a try.

vaderman1701 · 09-11-2010, 09:59 PM

Also, try using duplicolor High Build primer in combination with the spot putty. It works great.

Scott

modelnutz · 09-11-2010, 11:17 PM

Got to agree with that....especially the white sandable primer...smooth as a baby's behind

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09-06-2010, 04:48 PM	#1
Xyborg Join Date: Nov 2009 Location: Dallas, TX, USA Posts: 53 Thanks: 0 Thanked 0 Times in 0 Posts	FDM Prototype Smoothing I had some prototype Weighted Companion Cubes made with an FDM machine out of ABS plastic. One prototype is about 4" on a side, the other measures a little less than 1 inch on a side. I'd like to make molds to produce some resin or plaster copies, but I've never done this before. There's a bit of surface roughness that I'd like to smooth out. The only time I've done this in the past was with some Squadron green putty, which seemed to bond to the ABS plastic acceptably. Is there a better way to do this? I'm almost tempted to spray it with some crack-filling aerosol primer paint, but I don't know if this might mess it up or otherwise make the pieces unsuitable for mold making. Does anyone have any suggestions for how to do this?

09-06-2010, 06:43 PM	#2
modelnutz Join Date: Jun 2010 Location: East Aurora, NY Posts: 60 Thanks: 0 Thanked 0 Times in 0 Posts	Re: FDM Prototype Smoothing I do SLA benchwork for Fisher-Price and the fastest way that I've found is to spray the part with a good Lacquer based primer and then smear Acrylic Red Spot Filler putty all over the part...being sure to press the putty in to the depressions well. Let the putty dry for 12 to 24 hours...sand...prime...re-apply putty as required....sand....prime...repeat as required. Once you have a good smooth primer surface...I usually sand with 320 grit or higher for a very smooth plastic surface. Takes about 1/3 the time as sanding the raw part.

09-09-2010, 11:48 AM	#3
Xyborg Join Date: Nov 2009 Location: Dallas, TX, USA Posts: 53 Thanks: 0 Thanked 0 Times in 0 Posts	Re: FDM Prototype Smoothing Thanks for the detailed reply! I'll give it a try.

09-11-2010, 09:59 PM	#4
vaderman1701 Join Date: Jun 2002 Location: Baltimore, MD Posts: 657 Thanks: 0 Thanked 0 Times in 0 Posts	Re: FDM Prototype Smoothing Also, try using duplicolor High Build primer in combination with the spot putty. It works great. Scott

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09-11-2010, 11:17 PM	#5
modelnutz Join Date: Jun 2010 Location: East Aurora, NY Posts: 60 Thanks: 0 Thanked 0 Times in 0 Posts	Re: FDM Prototype Smoothing Got to agree with that....especially the white sandable primer...smooth as a baby's behind