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Your Layout and Models => 3D Modelling => Topic started by: Simon D. on February 19, 2020, 01:34:01 PM

Title: Strengthening FUD
Post by: Simon D. on February 19, 2020, 01:34:01 PM
There was a discussion recently on one of the US forums about the possibility of soaking FUD prints in something to make them less brittle, as they are pretty porous.  The initial idea was superglue/CA, but this is also brittle it itself.  Is there anything else that might work without obscuring detail?

Title: Re: Strengthening FUD
Post by: Snowwolflair on February 19, 2020, 02:48:10 PM
There was a discussion recently on one of the US forums about the possibility of soaking FUD prints in something to make them less brittle, as they are pretty porous.  The initial idea was superglue/CA, but this is also brittle it itself.  Is there anything else that might work without obscuring detail?

FUD has a solvent base similar to white spirit.  In fact white spirit will eat it.  However it can be used to carry molecules of something else into the surface structure which is porous but not into the core as its usually air tight.  One thought would be an enamel paint but you would have to immediately dry the white spirit out before it did any damage.

I find if you use a good quality undercoat (Halfords type) the surface strength goes up noticeably, but it must be left to dry and for the paint to cure as the molecular structure changes with time.
Title: Re: Strengthening FUD
Post by: Doc Pye on February 19, 2020, 02:52:07 PM
I would think something like AK's new range of Acrylic Lacquers might be a possibility, as they cover well and self-level. I tend to find all the Shapeways stuff to be a pain to clean up and get right, which is why I would prefer not to order from them...and also how darn expensive they are!
Title: Re: Strengthening FUD
Post by: Snowwolflair on February 19, 2020, 02:53:45 PM
I would think something like AK's new range of Acrylic Lacquers might be a possibility, as they cover well and self-level. I tend to find all the Shapeways stuff to be a pain to clean up and get right, which is why I would prefer not to order from them...and also how darn expensive they are!

Never file, I use a fibreglass burnisher to shine the surfaces.
Title: Re: Strengthening FUD
Post by: Simon D. on February 19, 2020, 03:35:59 PM
Thanks for the replies - some very useful tips.

I have read that this stuff: https://www.scalemodelshop.co.uk/products/paints/badger-stynylrez-primers (https://www.scalemodelshop.co.uk/products/paints/badger-stynylrez-primers) is a very good self levelling primer for the airbrush that I haven't got round to buying yet.  The various Mr Surfacer products are also good.

Simon
Title: Re: Strengthening FUD
Post by: Doc Pye on February 19, 2020, 04:20:51 PM
Stynylrez (also sold in Europe under the brands 'Ultimate Primer' and Mig/Ammo's 'One Shot Primer') is a must have when priming. It is self-leveling and covers well. I have heard some complaint about the white not covering all that well but I have never had any issues, and I mostly use white or grey undercoats for all my pieces. If your in the UK, as most of this forum are, then the Ultimate Primer is the same thing.

Title: Re: Strengthening FUD
Post by: maridunian on February 26, 2020, 04:28:57 PM
Although FUD is inherently brittle, models can be strengthened by designing to remove/reinforce obvious stress points.

Many interesting articles out there, including  this  (https://www.fictiv.com/hwg/design/stress-concentrations-how-to-identify-and-reduce-them-in-your-designs) and  this  (https://www.fictiv.com/hwg/design/best-practices-for-adding-ribs-and-gussets-to-3d-printed-parts-for-structural-integrity) from Fictiv who manufacture in a variety of materials and processes.

Mike
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