Best method of smoothing/levelling 3D printer PLA?

[43rdRecceReg]

I'm looking for the best option for levelling 3D printed PLA parts. An automotive acrylic filler/primer perhaps?
I found a guide here- but an 'acetone bath' sounds a bit more like disposing of a body, than smoothing a model off!
https://all3dp.com/2/pla-smoothing-a-beginner-s-guide/

It's not that I want any figures like these, but just a finish as smooth as these have, on an air intake for my Sherman project.
I've looked at Mr Surfacer, but that's more for a textured finish- well, at least the 500 version I have is.
All usable tips welcomed!!

[43rdRecceReg]

I saw this product, and it looks like a capable solution. Has anyone tried it? It's American, but there are UK outlets that stock it, apparently:
https://modelshop.co.uk/Shop/Item/XTC-3D/ITM7368

[General Jumbo01]

It looks as though that would smooth the finish rather like a varnish, adding a thin coat that would go off smooth. Alternatively you could use a paint finishing / finishing compound, available in various grades from any good car spares shop.

I guess it's your choice whether you rub off small detail or lose it under varnish! I'd avoid any form of solvent

[midlife306]

I’d avoid solvents on PLA, all I use are Swiss files, wet & dry sandpaper and elbow grease.
Oh, power tools are a nono..
Cheers
Wayne


Sent from my iPhone using Tapatalk

[Exhibitedbrute]

I would use and do use Vallejo putty apply spread by finger and sand smooth

[enginepeter]

Roy - I use combination of methods depending on the size of the part and its shape.

For the larger and flat surfaces I tend to fill with fine model filler/putty depending on what is to hand. Small irregular shaped pieces - a new X-acto blade and scrape it. For the rest a combination of sanding or filing. All a bit of a chore, especially the smaller pieces where I end up sanding my finger tips!

[midlife306]

A wire brush comes in very handy too


Sent from my iPhone using Tapatalk

[PatrickH]

you could try using water solouble resin and then cured with UV. Its what i'm using at the moment to smoothen out my pla prints

[43rdRecceReg]

Thanks, lads!. Yes, I would be too wary to use any form of solvent on PLA, and related 3D printed plastics.
I use wet superfine Milliput sometimes, and have also used Mr Surfacer; but Mr Surfacer tends to create textures, and I need a uniformly smooth surface. Also, Mr Surfacer is enamel-based, and contains solvent.

As a stopgap, I used a sheet of 0.2mm styrene. The air intake on the Sherman engine deck needs to be smooth, as it's made from sheet metal. I used superglue to bond a section of sheet to the printed filter:
So far, so good!.

[Model Builder 4]

Morning Roy,

If the area is flat enough I usually use the same method as you have just used, a thin piece of plasticard normally does the trick. For more rounded or difficult areas I use an automotive knifing putty and spread it across the surface with a piece of plasticard, this way you can get a little amount applied to just fill the printed ridges and once dry I just give it a quick rub over with some sandpaper to knock any rough edges off

Cheers,Lee.