What adhesive do you use to glue it all together and hide all the lines.
That depends on what material you'd be using to do the printjob.
Kristians' using PLA, his method of solder-ironing, essentially remelting the stuff works pretty well, but I admit I found it hard make precise, clean connections doing that. Using PLA, I used high-tac builder glue, stuff sold in Europe under the Tek7 or Soudal logo. It's not super glue : It's a paste-like substance which maintains a certain level of flexibility (very minute, it's not like your parts are wobbling. It's more that opposed to superglue, the connection doesn't become brittle after hardening).
A industrial tube of that stuff costs like 15€ or so. You can quite litterally glue bricks with it. I once glued a bad part to a prop and only noticed it the other day. I had to saw off the part as it was impossible to break the connection.
I switched to ABS+ for most of my prints, as it combines nearly all the pro's of ABS (superior termperature levels, quite a lot tougher than regular PLA) and doesn't come with most of the negative side of regular ABS (smell, terrible shrink/warp if you're unlucky). Still would need a enclosure to print ABS+ if your machine doesn't have one, but making an enclosure is really easy and can be done for 25€ or less and some time, inclusive Plexi-see-through door)
ABS(+) can be cold-welded using a mix of used ABS scrap (supports, failed prints, whatever) and acetone. Mix it up, let it melt in a sealable container. Add ABS or acetone till you reach the consistency you want to work, and just brush it on the parts you want to glue. Press the parts. Keep pressed. The acetone will evaporate pretty fast, then bond material will diffuse/melt the abs walls a bit, creating essentially a single-part. Compare it to what happens when you'd be welding metal, or the healing of a broken bone if you want. Once hardened, the connection is enourmously strong as you're not introducing any new material, and you're diffusing the surfaces into each other.
Thinner "ABS stuff" can be used to fill up cracks and irrularities or damages. Just brush it over/in the seam or damage, let it harden. It will become "one" with the surrounded material, and it can be sanded/post processed exactly like the original material.
Here's a demo of this procedure :
We take a badly damaged part (in this case, a split surface on an ODST helmet)
Pretty bad eh ?
Mix up the abs crap, take a brush, apply freely, inside, outside and IN the seam.
Let it evaporate. Handsand. 15 minutes later ?
And even in close-up, the only thing you'll see is a slight color difference :
As ABS has a pretty high glass transition temperature, you can either handsand or machine sand the part, but do use a wetsand technique.
The repaired part isn't just "repaired", it's as strong as a full, undamaged part.
501th Stormtroopers use this trick to keep their armors in good shape and seeing how easy it is, I totally understand why.
Also and this is pretty unique : ABS is slightly flexible compared to the pretty glass-like behavior of PLA. Well, a part which you'd repair like this retains that flexibility as again, you don't introduce any foreign material nor do you change the structure of the base material. You can even strengthen weak parts by just "painting it with ABS on the inside" and let it dry.
ABS can be a totall bitch during the printstage and I understand full well why there's a movement towards printing PLA. Several pretty expensive new machines don't even come with the basic fascilities (a heated bed) to work with ABS these days, which I find is a loss : because it's not just ABS that profits from a heated bed. Stuff like PETG likes a heated bed too, and even PLA can profit from it.
Anyhow, ABS+ behaves much more neutral and the printresults look "PLA-like" in sharpness and detail but just like normal ABS, I would not recommend printing it without an enclosure around your machine.
Some versions ABS+ even looks so similar to PLA, you'd be very hard pressed to see the difference, inclusive the PLA-typical shine.
One side is PLA, the other side is ABS+. Normally, ABS looks dull and somewhat less sharp. This stuff is .... different. I've joked about it saying it's ABS with an identity crisis.
The used material is from a company called "Devil Design", a European filament maker situated in Poland. They're pretty cheap even : I can get them for just below 16€ for a 1kg spool, inclusive VAT and what not.
