I’ve printed probably 5 kilos worth of prints with a lot of success, but exclusively PLA. I’d like to branch out to a new material. Should I start with ABS or TPU?
I’ve printed probably 5 kilos worth of prints with a lot of success, but exclusively PLA. I’d like to branch out to a new material. Should I start with ABS or TPU?
Thanks for taking the time to type out that reply, it packed a ton of information. I think you’re under selling the eye and the technique necessary to sand well. I’ve done some DIY auto-body and paint work and I really struggled to know when I had sanded well enough. Yeah, I knew I needed to sand more, but I had no idea where to focus my efforts and couldn’t easily distinguish a high spot that needed to get knocked down vs low spot that needed to get filled. Building that skill to the point of it being intuitive seems like something that would take a decent amount of practice or a great coach.
I hadn’t considered polishing ASA. I’m somewhat tempted to give it a go. The hardest thing for me would be figuring out how to sand large curved surface in such a way that doesn’t result in lots of obvious flat spots. I can absolutely see sanding/polishing making prints a bit stronger.
I’m sorry to hear about your physical condition and wish you as much additional recovery as possible. I totally get having very limited time with two younger kids in my house. I think all in the build took 4-5 months starting from printing parts, ordering a kit, and finishing assembly. Even though my kids are not new to me anymore, I don’t know that I’ve fully come to grips with the fact that I can’t complete projects as quickly as I once could and I should probably slow down my rate of project accumulation.
The real touch of a painter that is hard to acquire is only really relevant in the last layers of primer and sealer. It is possible to feel things that cannot be seen using fingertips over a panel. One of the aspects of this is simply part of the job. You'll wet sand so much as a painter that the skin on the fingertips is very thin. I worked until my fingers bled most days. That thin skin is always hot and super sensitive. It is possible to learn to barely graze the surface and feel the tiniest imperfections.
The main trick to calibrate touch is Wax and Grease Remover (a solvent). When W&GR is used on a panel it will briefly form a wet gloss. That wet gloss will simulate what the clear coat will look like but slightly worse because a 2k clear is much thicker and will level.
When sanding anything from fillers to high build primers, guide coats and sanding blocks are what matters. Blocks must be wide enough and shaped to bridge the issue. With most regular jobs that don’t require absolute perfection, curved surfaces are sanded by hand using a soft foam block.
Back in the day, I would have loved 3d printing and TPU because I could have made custom sanding blocks for jobs. Back then I used balsa wood to make special shapes when I needed them. I had probably three dozen or so sanding blocks for all the different issues I came across.
For guide coats, some people like a graphite like powder that is made for guide coats because rattle can enamel is absolute garbage paint and leaving any of it behind is a major risk under urethane paints especially the color coat. However, I still only ever used whatever junk rattle can I found on sale for a dollar. You only need a light speckled but consistent dusting of a guide coat. The sanding block will show the highs and lows. Just be sure you’re using the block like a rolling pin and not like a scrubbing brush. You can even use a guide coat with sanding prep for polishing work.
There is not a ton of skill in this area. A few tips about techniques is all it takes. The real skills of automotive paint are in tinting colors to match the degradation of an existing finish, matching orange peal, and primarily knowing how to best remedy situations when things go very wrong. All the various ways paint can react badly are complex problems and those lessons are hard won with bad experiences. Most can be avoided with meticulous cleanliness at the earliest phase of work.
I don’t do well with very long project timelines. I think it is quite remarkable that you can last for 5 months on a project with kids and all the distractions that entails. Sleep deprivation puts me in situations where it is like my mind is wiped every couple of months. I just don’t care to get back into a complex project and lose my motivation to some new curiosity. I tried to fight it at first. I was only like this after disability. It just becomes a depressing spiral and I don’t tend to finish very much. Hopefully that changes. I have several nearly completed projects I would like to finish, but oh well. Kids would absolutely drive me nuts, but I am at pain levels with sound and some light sensitivity 24/7.