Tuesday, 1 March 2016

A Big Box

A big box arrived from Shapeways today. Although I've got several things on order it contained  just one small bag, inside of which was this:


  1. Printed in FUD? Make sure it gets plenty of sunlight to set the resin.

    1. Really? I've been using FUD for ages and never heard that suggested before. Yes it will need a quick bath in whitespirit to remove any remaining oil and then probably the faces burnishing slightly. I've built lots of FUD prints now and haven't had any deteriorate yet, and none have been exposed to long periods of direct sunlight before being painted etc. Do you have a reference to explain why sunlight?

    2. Phil, Yes FUD. Exposure to wind we can do round here, sunlight might take some time. Fortunately I've got time because I spent the chassis fund on a turnout for the 7 1/4" line.

      Mark, Would a fibreglass pencil work for burnishing?

    3. Iy's not oil that's coming out of the FUD, it's the resin it's made from. The material is cured using UV light and Shapeways don't always give it enough of a dose to penetrate deep into the material.

      Source: https://matthewsmodelmarine.wordpress.com/2015/12/01/painting-shapeways-frosted-detail-plastic/

      I have a FUD telephone box that never seemed to dry and resisted all paint. If I'd left it in the sun, or better still a UV lightbox, it might have worked better.

    4. Phil, I'm not sure that's accurate at all. While FUD is a UV cured resin, my understanding from a shapeways employee is that the stuff left on the print is an oil that's used to help wash away the support material. They do wash most of it off but they don't treat the prints with whitespirit (or similar) to remove it all as that usually makes the print opaque and rather then mostly transparent. They actually mentioned in a support forum thread recently about possibly offering an option where you could request a more solvent wash to deal with the problem. I do remember an article on a phonebox where the paint wouldn't dry (which I assume was yours) and vaguely remember thinking at the time that the description didn't talk about properly washing off the oil in the way I would have done. I've had some really slimy prints over the last few years and a quick bath in whitespirit has cleaned every single one and I've never had a problem with paint not drying.

      James, yes a fibreglass pen would work although I've found rubbing a wooden coffee stirrer over the surface often works well. The problem only really occurs where support material has slightly altered the surface texture, so you'll need to have a look at the model to work out which bits need work and which don't.