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So, one of my ongoing stupid projects is I 3D print big ol' kaijus, mostly Godzillas. When I do so, they are printed in big sections. Those sections don't always fit together perfectly - sometimes they are nice and tight, but sometimes there is a gap of as much as 2mm or so. Since I don't want a garbage looking model, I must blend the sections in by filling and smoothing the gaps, and sculpting detail as needed. If it's a very tight gap, I carefully run a little 3D printing resin in there and blast it with a UV flashlight, very fast and easy Of course, that only works if it is a smooth, tight gap with no detail to recreate.

For wider gaps, or if I need to recreate detail, then I use Kneadatite (greenstuff), since as a Warhams person that is what I have and know. That works pretty well obviously, easy to use, easy to sculpt... but it is a little tedious when I need to fill a gap that is really long. For example:



Anyway that brings me to my current predicament: I have a model that is really, really big, and has a few section gaps. In this case one of the gaps is about 3mm wide and about... 25cm in diameter.



That's no longer a job for greenstuff, it would take forever. The GOOD news is that there is very little detail in that section, it's pretty smooth.

I am hoping to find a soft putty I can slop into those gaps and that will air-dry without shrinkage or cracking. I am considering Milliput or Aproxie Sculpt, but I have never used either of them. Can people who are familiar with them tell me what they are like, as compared to Kneadatite? It's gotta be something I can wipe down/clean up with water, additionally.

Note: does not need to function as an adhesive - the sections are already glued together. Just as a filler.

Thanks!

I've never worked with Milliput but I have worked with Apoxie Sculpt.

It cures hard almost like pottery, but it's easy to work with and cleans with water. You can even smooth it out with a wet fingertip. Apoxie Sculpt is not as sticky as green stuff, so that can make it a little challenging at first.

But for filling in Kaiju gaps, Apoxie Sculpt would be great!

I know this is hard to quantify, but... how soft is Apoxie when it's first blended?

I would go with milliput. Cheap and perfect for this kind of quantity. Sets nice and hard and is sandable for a smooth join.

A bit off topic but from my experience, these gaps occur as a result of the mortice & tenon being designed without consideration for the printing tolerances.

Workaround for reducing the gaps is to alter the dimensions of the tenon to 94~97% of original scale/design or increase the scale of the mortice by 103~105% (or boolean difference it), or filing it down with a dremel.

Would it make things easier or more economical to roughly fill the gap with some sort of shim, and then use putty just along the "rim" of the gap? No experience with this task, just brainstorming.

Green stuff is by far the toughest of the 3 sculpting materials, and has a very different feel; green stuff is plasiticy (hard to explain but you know if you’ve used it) whereas both apoxy sculpt and milliput are much more clay-like. They are both much softer than green stuff, and sculpt well but they do not stretch in the same way as uncured GS does; it makes them much more flimsy for thin, long details and the like.

Milliput and Apoxy are pretty similar, but I would say Milliput is a bit softer. Both can feel very hard right out the pack but they soften quickly as you knead them and they warm up.

Milliput is very water soluble, and apoxy sculpt less so (though it does seem to be soluble to some extent, unlike GS) this does help when it comes to cleaning it up (as you mentioned). That being said a word of warning: more water added = more shrinkage. Milliput straight from the pack will not shrink when it cures, but if has been mixed even a little with water you will see some shrinkage. Again, apoxy sculpt is pretty much the same in this regard but less soluble.

A 50/50 mix of green stuff and milliput is what I would use for a job like that. That mix adds a lot of softness to the GS while keeping its plasticy texture which i find is easier to work with than pure milliput.

Apoxy sculpt is a lot more expensive and harder to find than milliput, and I don’t think it offers a significant benefit in this case to be worth picking it up just for this. Besides, i would just used GS mixed with Milliput or just straight milliput either way

While we are talking about milliput, this video might interest you?

Assuming those two pieces aren't yet permanently joined to each other, here's what I'd do: Roll out a thin sheet of Milliput between silicone baking paper sheets, about the same thickness as your gap. cut out a hole for the joint, slap it on one side, squish the two parts together with whatever glue you're using on the joint. Trim off the putty that squidges out of the joints. Milliput handles like rather sticky clay. Let it set up for 15 minutes or so before you try to sculpt any surface details on and it'll behave better, like most epoxy putties.

I explain green stuff as two component plastic mix. I am not shure if that is accurate.

Milliput is probably best for big gaps like that. It's easy to mix, you can ram it in, it cures very hard and can be shaped easily after about 15 minutes, then cut and scraped once cured.

You can also mix milliput with GS to create a putty that combines the qualities of both. Basically it gives a nice smooth material, but cures harder, without the elasticity you get with green stuff alone.

So you could do the main gap fill with pure milliput, then use a mix or GS to finish the details

I've used Milliput for large gaps with reasonable success. You can also combine Milliput with Kneadatite to get the best of both putties if you need the hardness of milliput but also some of the detail retention of kneadatite.

If you have an Instagram I highly recommend checking out a bloke called @modernsynthesist
He's a very knowledgeable sculptor and has plenty of good tips and tricks to impart. He also runs a quite valuable youtube channel by the same name. He's a huge advocate of Ave's Apoxie sculpt and uses it extensively along side Kneadatite. Well worth checking out for some good general sculpting know-how.

 Ouze wrote:

Anyway that brings me to my current predicament: I have a model that is really, really big, and has a few section gaps. In this case one of the gaps is about 3mm wide and about... 25cm in diameter.

For this very specific use-case, I'd actually use builder's acrylic caulking (in a cartridge gun with the nozzle cut to the smallest hole possible). A water-based one that is stated to be directly over-paintable. Then smooth it off with a wet silicone tool (a clay-shaper would be fine).

In reverse order:

Thank you to the many people who suggested Milliput and/or mixing Milliput and GS. That is what I am going to try out, the Milliput will be here this weekend.

tauist wrote:While we are talking about milliput, this video might interest you?

It would and did - thank you!

Hankovitch wrote:
Would it make things easier or more economical to roughly fill the gap with some sort of shim, and then use putty just along the "rim" of the gap? No experience with this task, just brainstorming.

This is a pretty good idea - I might do some rough fill-in with a 3D pen I have. It's not particularly good for the stuff they pretend you can do with it, but it's pretty spectacular for filling voids with a lot of PLA or repairing small damages.

skchsan wrote:A bit off topic but from my experience, these gaps occur as a result of the mortice & tenon being designed without consideration for the printing tolerances.

Workaround for reducing the gaps is to alter the dimensions of the tenon to 94~97% of original scale/design or increase the scale of the mortice by 103~105% (or boolean difference it), or filing it down with a dremel.

It's not at all off-topic I think one of the factors here is my FDM prints tend to have elephant foot for anything on the plate, so my lack of a perfect dial-in contributes. I already try and clean up the join as closely as possible since as you can imagine, 10 min of work with the dremel tool can replace many hours of tedious filling. In the case of the depicted print, I actually used a dremel tool to take off about 10% leading edge of the tenon to try and alleviate that with not so great results. I am considering taking off the entire tenon to try and get a better fit but... that might be a bad idea since it's a heavy model and it's load bearing, functionally.

While this is good adviceI don't think I've got the modelling skill to rescale the mortice\tenon in Meshmixer the way you suggest in a way that will give me a better result, honestly. I expect I would make it worse.

It's almost a moot point now - this is probably my last super jumbo FDM kaiju print. The new large format resin printer does not have these issues (the joins on the Kong are so tight they stay in place with no adhesive) and for me that is the future of creature prints.


In between this and the "white paint" thread, I am well reminded that you can be in this hobby for a long time and still have so much to learn.

For something that large I'd actually use construction adhesive from a box store like Lowes.

There just isn't going to be a scale model option that would be worth plugging a gap that size IMHO, plus this will give you a really solid model. You can always wipe carefully with moist cloth part way through setting up to get rid of squeeze out.

IDK, sometimes I get focused on the industry I am doing a project in and forget to look a bit broader, I hope that helps you out.

I have stuffed tin foil into large gaps so i only need to put on a top layer of putty - this also saves a ton of material.

I wanted to thank you guys for the recommendation of Milliput. I finally broke it out today and it's wildly better for this specific application than kneadtite has been. What would have taken me many, many hours I had done in about an hour while on a work conference call. I didn't wind up needed to mix in kneadatite after all, I just used milliput straight and carefully washed down the surfaces to smooth it out.

I did use my 3D pen to squirt some soft PLA into the very worst of the gaps, so that helped a bit too.

The one thing I learned - well, two things - is that it's a lot stickier than I expected, but letting it sit for about 20 minutes made it just about perfect. The other thing is I really should have worn gloves - in addition to being very sticky it also was (very slightly) irritating to my bare fingers; something that happened once before with plumber's spackle. Not enough to hurt or be raw or anything, just enough to be slightly irritating.

I have a absolute ton of nitrile gloves because of all the 3D printing so that isn't a problem, just a note for anyone else who might read this thread in the future.

Sounds like a job for cheap plumber's putty. It's my go to for almost any gap filling. It hardens pretty quick so it's not good if you need to sculpt details

I find milliput drys the skin and then starts to stick to it quite badly so wetting your fingers is important or as you say wear gloves.