manually fixing pla?

Hi, I have a print that is 98% good but has a couple of patches of thin bridging with very small holes. I want to use the part as it was a 14 hour print and its good enough in all other respects. Is there a way to manually add pla to patch up these holes? Any tips?

Im thinking about using a soldering iron with a tube of pla like solder to thicken it up and then sanding it down. Anyone tried this?

Also if anyone can also answer, how the heck are you supposed to remove a print from kapton tape?

Cheers

Epoxy brushed into the holes will do fine. I shudder at the thought of using an iron. That's an avalanche of problems waiting to happen.

Will something like modellers glue melt the plastic then?

What type of modelers glue. I know CA glue holds ABS and polystyrene fine, I'm not sure if I've used it on PLA though, but it should work.

Print out a small item (like 20 minute print tops) with an intentional weak spot/joint, and use the glue you have. See if it works.

did you see this youtube video? https://www.youtube.com/watch?v=xBISSRcHRGE
if the hole isn't too large, friction welding can fix it.

I always thought of soldering iron and PLA filament, almost like a TIG weld. I might try it just for kicks.

if you want to "Weld" plastic... get a length of filament and put it in a dremel, use this as your MIG (not TIG) weld. The friction will melt all surfaces enough to "wled" them together. An iron is going to burn, not melt them, and if you do get melting, it will be difficult to control where you are melting. Plastic is NOT solder, it will not quickly melt and solidify. It'll take time. That time will lead to the end of the world. Don't use a solder iron.

It's worth investing in a cheap 3d printing pen. These are great for filling holes, patching things up and - what I use it for most - heating the tip up to the right temperature to melt and modify plastic prints.
I have one of these: http://www.ebay.co.uk/itm/3D-Printin...item4ae03fad0b
Works great.

As to removing a print from kapton tape. Yeah that can be a right bastard.
The 'trick' is to calibrate so that it sticks but does not bond.

Geoff recommends sanding the tape to reduce the stick - seems to work, a bit lol
That and a slightly looser calibration than i use for abs helps.
Some weeks I get it spot on and can remove prints and leae the tape intact, and some weeks I repelce the tape after every sodding print. There are a lot of factors involved. And everyone's workshop has different environmental conditions to account for.

You can scrape it off with a sharp knife, or soak it off in warm water.
If you use polymakr polyflex - you just have to wait for it to wear off :-)

But all of these things are better than it not sticking at all :-)

Glueing bits together - abs or pla I tend to use uhu clear all purpose glue.
It's nearly as fast as superglue and a lot less brittle.

Quote:

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Originally Posted by Marm

if you want to "Weld" plastic... get a length of filament and put it in a dremel, use this as your MIG (not TIG) weld. The friction will melt all surfaces enough to "wled" them together. An iron is going to burn, not melt them, and if you do get melting, it will be difficult to control where you are melting. Plastic is NOT solder, it will not quickly melt and solidify. It'll take time. That time will lead to the end of the world. Don't use a solder iron.

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Haha this is a great idea. I'm so used to welding that I automatically thought of hot blobs and creating the stacked coin effect that looks so pretty. Won't happen with plastic I guess!

How long of a piece of filament can you put in a dremel before it starts to turn into a weed wacker?

There are several videos of this technique on Youtube. Here's just one.

Not very long, a centimeter at most I've found. Takes a little practice. But yeah, once you get the hang of it, it almost feels like a Tig/Mig torch.

And I usually put on safety glasses, and on occasion I've wished I had gloves. Little molten blobs sting.

- Eddie also posted a neat little article on 'Friction Welding' HERE

This is one technique that works pretty well for removing from Kapton tape. Take a utility knife, the large type with the sliding blade that breaks off in sections. Side the blade out as far as it takes to reach the part while keeping the blade almost parallel to the bed. Work the tip of the blade under a corner or edge of the part, again keep the blade as level to the bed as possible. Once you get even a tiny bit of the blade tip under the part then take another tool, a small narrow putty knife and slide it under the blade between the bed and the blade. This will put enough upward pressure to get a little more gap. If necessary while leaving the putty knife in place reposition the knife blade again under the part and repeat the process, slowly pushing to wedge the part up.

Using this I can usually get it off without damaging the Kapton tape at all, and if I do it's a small nick where I started.

Also part of this is putting the tape on the bed well to begin with. Use the soapy water and credit card to get a good seal. There can be no bubbles at all under the tape, none, those spots will rip up when prying the part up.