Filling and Sanding Prints

[bauermaker 0]

Hi Everyone

I just decided to start a thread describing my modus operandi filling and sanding my models after printing.

I will be happy to answer any questions and i will be posting my experiences with different brands of filler (either spray or tube based) and different kinds of Filament.

Here are work in progress shots of a project i did a while back for renault austria.

 

I took me about 4 days to get it done and it involved a lot of sanding and a little bit of reconstructing (the cabin was to short at first ad i had to ad an extension in the back)

 

It was printed in orbitech 90, fillered with generic spray based car filler from the hardware store,tamiya putty (ebay) and Moltofill wood.

 

this was the finished result

 

 

[bauermaker 0]

Wet sanding is the most important thing to do to get a good finish.

I start with 220 grit and work my wayup to 1000.

After one pass of sanding i dry the model and go outside to give it a coat of filler.

After this coat i can spot the bigger flaws that i have to touch up with putty or bondo.

then i sand again and repeat the steps until i am satisfied (can take for eeeever)

One of the bigest problems is, to get to difficult to reach areas on your model.

With the truck i ended up having to split it in many different parts to be able to get in to every nook and cranny,

I sometimes use a Dremel but mor often than not end up ruining some of the small deatails because the Material starts to melt.

 

[mnis 11]

You definitely need no help, it all looks lovely. A truly successful work, congratulations.

I have read a bit about TETRAHYDROFURAN (THF). Vapors may PLA surfaces smooth. Similarly it behaves so in acetone for ABS.

Whatever, THF is harmful and generally very dangerous. The handle is reserved experienced users, and safety regulations must be complied with mandatory. THF is a solvent for PVC, polyurethanes, cellulose nitrate, adhesives and coatings.

In joyful admiration for your work.

Markus

 

[s.partridge 0]

Nice, but how do you stick back together the parts for the hard to reach places?

I'm struggling to find a decent glue.

Tried superglue and it works alright but not very strong

Tried epoxy resin, few minutes to set but kind of weak bond as I pulled it off next day with ease

Next i'll try model glue, hoping it can chemically melt the plastic to bond together...

Any ideas?

 

[mnis 11]

I have no experience with the sticking together of PLA components, not yet with the use of THF.

The contact surfaces must be dissolved so that good connections will be established, superglue and acetone can dissolve PLA probably not. PVAC and THF can dissolve PLA, I think.

When using super glue the contact surfaces should be lightly roughened.

But I think normal wood glue or waterproof wood glue could be good Adhesives for PLA. Diluted wood glue based on PVAc is also frequently used for the first layer for better adhesion when PLA printing.

White glue (wood glue), commonly known to us as Ponal containing PVAc.

The universal glue, commonly known to us as UHU, for example, contains 40% PVAc.

Common adhesives:

UHU, UHU plus, UHU plus 300, UHU allplast, Loctite 401, PVC glue, Ponal Classic, Ponal Express, Ponal Construct, Ponal Waterproof...

Markus

 

[s.partridge 0]

That's great thanks, I was thinking that it needed to "melt" for a true bond. I'll look into your suggestions thx

 

[mnis 11]

Fine, if you have found a good working method, then please let us know.

Markus

[bauermaker 0]

Hi

I used Aero - Bond Superglue and Activator Spray for most of my projects:

http://www.ebay.at/itm/2x-AERO-BOND-SET-Sekundenkleber-dickflussig-dunnflussig-mittelflussig-Aktivator/191113158919?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D7433579352415654656%26pid%3D100015%26prg%3D1006%26rk%3D4%26rkt%3D4%26sd%3D140446190029%26clkid%3D7433580573406291077&_qi=RTM1685972

Some people are reportedly also using Loctite Products.

 

[bauermaker 0]

So, this is my active project.

I modeled Bobas head ages ago and finally finished the body (i used a different model as a base mesh)

I printed it in one piece and so far only sprayprimed it twice. Currently i am sanding and manually filling.

Its approx 12cm high and will also feature his rifle and the jetpack-

I will regularly update the work in progress and write about it.

When i am finished i will post the model on youmagine (there are still a few errors in the stl that i will have to fix ...)

thats it for now

b

 

[bauermaker 0]

Long time no write...

I didnt finish the boba fett but focused on the belgian red devil instead.

I will repost the photos here and will go into a little bit more detail on the wet sanding process (Nicolinux asked about it and i remembered about this thread

I use standard sandpaper that i can find in the local hardware store, its black and the labels say its for metals and plastics. I think it starts at grit 40 and goes up to 600

for higher grit (1000, 2000) i had to go to stores specialized in modelmaking and rc controlled planes.

I usually cut or rip of small pieces and dip them in a bowl of water. then i start with low numbers (180 or 240) and work my way up to 600 or 1000.

It can take a long time to get a perfekt finish.

on the pug model, i spent at ;east 10 - 15 hours, most of it on the head (too many folds) and the belly (there were too many polygons still visible) and on making the parting lines go away (the model was printed in 3 parts)

 

 

This is the pug right out of the printer, the head was in the first stage of sanding

 

 

at this stage i realized that i needed a lot of putty to get rid of the polygons on the belly, i even considered reprinting

 

 

this was after glueing all the parts together

 

 

The paint job is a different story i might tell in a future update, it involves bad airbrush paint from the states, acetone and a failing airbrush ...

 

... but i actually really like the way the paint turned out

 

[mnis 11]

Wow ...

A few hundred likes, by me, for your excellent work.

I am very curious to see what other things you want to show us later.

I would not have the patience and calm for so time-consuming work, but you it seems to give pleasure.

Please keep it up.

Markus

 

[bauermaker 0]

thanks, i mostly do it when i should be doing much more boring work or during breaks from sitting in front of the computer.

also watching bad television series where you dont have to look at the screen helps a lot

 

[drayson 75]

Great work Bauermake!!

Btw: where are you from? Noticed an .at ebay link from you...

[mnis 11]

Could you make a Sonic for me?

So something like this: http://www.thingiverse.com/thing:258625

Maybe someday?

Markus

 

[skint 61]

Bauermaker Your results after sanding are superb! You really have a lot of patience, and it shows. I should work on my own patience, its not too good lol

 

[bauermaker 0]

@skint patience is a virtue

normally i am a very impatient man, and the sanding process is always killing me because of how long it takes.

the pug models took me weeks to complete because i always got sick of sanding after a few hours ...

but the results and the reactions on this forum keep me motivated

 

[bauermaker 0]

Great work Bauermake!!

Btw: where are you from? Noticed an .at ebay link from you...

 

Hi

Lustigerweise bin ich auch aus Graz

 

[drayson 75]

:-) Cool - sollten uns mal bei nem bier austauschen :-)

[Nicolinux 288]

Hey guys another question. Do you use some kind of paste for/after wet sanding?

 

[bauermaker 0]

@drayson Bier sehr gerne, wo bist du denn normalerweis eunterwegs

@Nicolinux I tried some pastes (Polierpasten) but wasnt able to get good results. or to be more exact, i didnt notice much difference after using the paste.

One exception was woodfill, because it doesnt react to good to sanding (turns white) so i used the red paste from dremel to get the brownisch finsih back

 

[drayson 75]

@drayson Bier sehr gerne, wo bist du denn normalerweis eunterwegs

 

@ Bauermaker: Wenn, dann eher im Univiertel oder mal Parkhaus (wenn das Wetter passt) - aber das kommt beides leider sehr selten vor. Würde vorschlagen, wir reden uns über PM zusammen, um ned den thread zuviel mit offtopic zu belasten :-)

Maybe it is time to generate some kind of postprocessing tutorial...

I´m also very interested in as I usually get really bad results when trying to sand or polish my prints - therefore I stopped doing it...

 

[bauermaker 0]

Hi

I had some time to play arounf with the bronzefill material and have to say that i love it.

at first, i had some problems tog et rid of the underextrusion but since i fixed it i had a blast.

It prints like woodfill, so you dont really see any printlines.

this was done with 0.06mm, 215 temp, 45 speed and 105 flow on my new UM2

 

to get this finish i used my dremel and a metal polishing attachment. after a few minutes i hat this finish.

 

http://www.dremeleurope.com/at/de/ocs/category/6033/reinigen---polieren

 

right now i am really pleased because this technique gives me the possibility to get a very nice and special fnish without the usual hours of sanding and filling....

 

i will experiment some more and keep you üposted

 

b

 

[Nicolinux 288]

Which Deremel attachment did you use exactly?

 

[bauermaker 0]

Hi Nico

http://www.dremeleurope.com/at/de/ocs/product/6039/172/drahtb%C3%BCrsten/drahtb%C3%BCrste-19-mm;jsessionid=CE05EE1A7DCC6609BDA1031F96ADAC88.sl021-vm_1

this is the exact one is used, but i am planning to get all of them to be more flexible, i also thought about using a "Drahtbürste" sinsce they also come in different metals.

 

[Nicolinux 288]

Alright, thanks. I also have a Dremel and was thinking about expanding its feature set