Dying 3D printed resin parts

[Dr PR]

I occasionally see posts where modelers have created cannons or anchor chains with 3D printing. The tiny bar-link anchor chains are a special problem because paints often act as glues to fuse the links together. A modeler (Hank) posted a useful tip of The Ship Model Forum for blackening anchor chain. I have experimented with this a bit and here is what I have learned.

 

This is the TransTint water/alcohol soluble black dye. It is about US$24 for 2 ounces (59 ml). For staining porous material the instructions say to dilute the dye 1:32 in water. I tried this with different staining times, and also used the dye undiluted. Here are the results on a 1:96 scale US light cruiser bar link chain with links that are 3.9 mm x 2.3 mm x 0.66 mm "wire" diameter (the rod the chain is made from is called a "wire"):

 

 

The top chain in the photo is an early experiment with an excessive exposure time that caused the links to fuse - so it made a good test subject. But it shows the original color of the Anycubic Basic Grey resin.

 

The second example was stained for one hour in the 1:32 diluted dye and dried overnight.

 

The third from the top was stained overnight (>8 hours) in the 1:32 diluted dye.

 

The bottom example is a section of freely articulating bar link chain that was stained for one hour and dried on a paper towel in air overnight.

 

The middle two examples aren't much, if any, different. So the staining time doesn't make much difference. These chains are too light. The bottom chain is satsifactorily black. Some of the links were lightly fused after dying, but a gentle twist of the chains set them free.

 

I noticed that some of the black dye rubbed off on my fingers when I was handling the chain. I folded a damp (with water) paper towel around it and a LOT of pigment washed off. After it was dried it looked like this:

 

 

It was still very black and none of the pigment rubbed off with handling.

 

I dyed a bunch more chains and after drying held them under a slow stream of warm water. A short (one second) plume of dye washed off and then the water was clear. The dried chains are very black and completely flexible.

 

So I think the best procedure is to dunk the chain (cannons) in undiluted dye for an hour or so (maybe shorter) and air dry for several hours. Then wash it for a few seconds in water and let it air dry.

[allanyed]

Hi Phil

 

I have cannon barrels made with black resin so there is no need for dying them.  Do you know if this could this work for the chain as well?

 

Thanks

 

Allan