Jump to content
Ultimaker Community of 3D Printing Experts
Edel

Problem with Smooth-On XTC-3D, no good covering…

Recommended Posts

I bought now XTC-3D, to get a clean, smooth finish without sanding….

But actually its not as good as they describe it.

I mixed it as described, 1Parts to 2Parts used a Poly-brush to apply it

very thin! not as much, i saw in the youtube videos...

After 1 day dwell time:

http://youtu.be/dNA-z8U7zHw

You see a lot of spots.... and also a light irregular thickness of the xtc-3d...

the last side i still sand down in the video.... and then you see directly the next problem, the covering..... because this is not constant, i got small discontinuities....

yes you can say holes!!!

5a3320c7124ee_Foto28_08.16192559.thumb.jpg.fbf4267be69780530330fe5c45243dc8.jpg

5a3320c75256e_Foto28_08.16192609.thumb.jpg.0aeb18d2551692411f1e653c49a96538.jpg

5a3320c78a734_Foto28_08.16192625.thumb.jpg.4291d5a89483f81c68feefeb4e630384.jpg

so as you can see, because of the spots, i sanded now the xtc cover, but you also see then the holes :(

what do i wrong?

how can i fix it? with a 2nd layer of xtc???

because if i paint this parts, with holes now, they look like:

5a3320c7c708c_Foto28_08.16192820.thumb.jpg.436b33c94d671348e5b43f2962d1e5cb.jpg

5a3320c80b571_Foto28_08.16192730.thumb.jpg.4a3c4c890191043c99862283432bfb43.jpg

und das sieht leider keineswegs so glatt und gut aus, wie es soll.

but what do i wrong :(

5a3320c7124ee_Foto28_08.16192559.thumb.jpg.fbf4267be69780530330fe5c45243dc8.jpg

5a3320c75256e_Foto28_08.16192609.thumb.jpg.0aeb18d2551692411f1e653c49a96538.jpg

5a3320c78a734_Foto28_08.16192625.thumb.jpg.4291d5a89483f81c68feefeb4e630384.jpg

5a3320c7c708c_Foto28_08.16192820.thumb.jpg.436b33c94d671348e5b43f2962d1e5cb.jpg

5a3320c80b571_Foto28_08.16192730.thumb.jpg.4a3c4c890191043c99862283432bfb43.jpg

Share this post


Link to post
Share on other sites

oh noooooooo,

I am very scared to chemicals, therefore XTC was ideal for me.

this is therefore the reason, why i dont want to use abs with acetone.

There must be something wrong somehow.

Mixture?

Nitro dilution? to make it more like water?

The product is ok, but i dont understand, why Those are hole :(

and how i can fix it

Share this post


Link to post
Share on other sites

Hi Edel, I have used XTC but have not experienced your problem. Indeed the results have been excellent. Th eonly problem I suffered, on non horizontal surface was the coating creating "runs" and it took some practice to overcome that.

This is a pic of a part which subsequently had to be spray painted by the customer and it is entirely smooth. It was printed with .300 layers and a 8mm nozzle. The .stl was created from a scan which introduced some imperfections, not present in in the final Solidworks model.

uf1.thumb.jpg.c80ff1f31762b6f923297fc9ce0e5d16.jpg

One issue was that whilst smooth it did not look great to the end customer so we added some of the XTC colouring to the mix. As you can see the 3D printed layer lines etc. have disappeared.

uf2.thumb.jpg.f3a37e9269760e62dcd40c49de71525f.jpg

The two "blobs" ringed in blue were a result of the "running problem I mentioned, now overcome. If you look at the strut on the right, at the lower left corner you will see some roughness on the edge which is a result of the scanned image.

Back your problem - I can only assume either

1. you did not use an accurate measuring cup to mix your coating, or

2. you used a cheap brush which did not coat very well, or

3. maybe you suffered some shrinkage, very strange though, I have not, or

4. maybe you were not using PLA, I have only used XTC on PLA or

5. as you are using the clear coating did you really check all over to make sure you had not missed any areas?

Certainly for me the first two or three I did were not 100% perfect and I needed some more attempts before I was able to prevent the "runs" appearing.

Also once you mix the solution you have to work quickly as XTC starts to cure quickly, 8 minutes? I forget.

Also for this part I printed a jig which fitted on the bottom so that could rotate the part as I coated it without getting my hands on the part itself.

uf1.thumb.jpg.c80ff1f31762b6f923297fc9ce0e5d16.jpg

uf2.thumb.jpg.f3a37e9269760e62dcd40c49de71525f.jpg

Share this post


Link to post
Share on other sites

So, its a little bit late for this topic to bring up again but so:

Xtc 3D generates Heat if you are mixing it. More that usual.

That means you only mix it as long as directed in the description.

If you mix it too long heat will really go up. If you brush it on your print it will melt that plastic down.

Hope i helped you

Lg Hannes

Share this post


Link to post
Share on other sites

So, its a little bit late for this topic to bring up again but so:

Xtc 3D generates Heat if you are mixing it. More that usual.

That means you only mix it as long as directed in the description.

If you mix it too long heat will really go up. If you brush it on your print it will melt that plastic down.

Hope i helped you

Lg Hannes

 

ich habs seit damals nicht mehr benutzt! wie kommst du aufmal auf das thema hier?

hast du den eine deutsche anleitung?

das habe ich jendenfalls noch nie gehört mit der hitze, wie lange sollte man es mixen?

Share this post


Link to post
Share on other sites

Just use acetone on 0.06mm layer prints, its a lot easier, less messier and has no problems with sharp corners either. But this XTC 3D might be better for 0.1 mm and lower layer prints

 

1. XTC 3D is for those people who dont want to risk their life for an stupid method how to clean 3D Prints

2. Acetone works only for ABS - so for PLA it would be Chloroform which is extremly dangerous because it is generating fumes.

SO, now to Edel:

Ich komme auf dieses Thema weil ich es mir selbst bestellt habe um es mal auszuprobieren. Dabei bin ich auf dieses Thema gestoßen. (Übrigens es funktioniert super) Nein, ich habe keine deutsche Einleitung, ich habe nur die Beschreibung komplett durchgelesen. Du solltest es vor gebrauch schütteln, zuerst PART A und dann PART B (Part A 2/3 und Part B 1/3) und dann für 30 Sekunden gut mischen, aber nicht zu schnell, im Normaltempo, sodass es gut umgerührt wird. Dann gieß du es auf ein Alufolienblatt (Weil das Risiko besteht das es so heiß wird dass es den Plastikbecher schmelzen kann) Übrigens: immer Handschuhe tragen und JEDEN Haut oder Kleidungskontakt vermeiden. Schutzmaske wäre zu empfehlen. Dann trägst du es mit einem Pinsel auf und streifst so lange drüber bis keine Luftblasen vorhanden sind. Dann lässt du es trocknen, optimal mit 220 Schleifpapier bearbeiten und du bist fertig.

Kannst ja mal ausprobieren :)

Würde mich freuen wenn es dir geholfen hat.

Lg Hannes

Share this post


Link to post
Share on other sites

I am very scared to chemicals, therefore XTC was ideal for me.

 

XTC-3D is a chemical too. So it may also have health-risks, similar to any other chemical.

About XTC-3d, from the Smooth-On website: "Avoid eye and skin contact. Avoid breathing fumes - use in a well ventilated area. NIOSH approved respirator is recommended. Wear safety glasses, long sleeves and rubber gloves to minimize skin contact. This material has a high exotherm (generates heat). Do not mix components in glass or foam containers."

The MSDS also mentions that it could cause skin burns.

Whatever chemical you use, you need to inform yourself of the risks, and then take proper precausions to prevent any harm. It it is the way you handle a material that makes it safe or not. Even "harmless" water or air can be deadly if handled the wrong way.

By the way, water is a chemical too, even though we don't usually see it as such. :)

Edited by Guest

Share this post


Link to post
Share on other sites

@OmegaCO - Listen to cloakfiend. He is the world expert on using acetone to smooth PLA as far as I can tell. He has one of the longest topics in this form and it's on this subject. He has videos. He has many pictures. His technique keeps changing and getting better. This is his specialty.

https://ultimaker.com/en/community/10412-acetone-finishing-on-pla

  • Like 1

Share this post


Link to post
Share on other sites

I'm way late to the party and signed up just to respond (I have a different 3D writer, but I wanted to contribute something I didn't see already posted (or maybe it was just in German).

I have had similar problems and the issue seems to be dirt or some other material that prevents the surface from wetting properly. The coating seems to brush on OK, but then patches thin as the resin retreat from these regions, and the spots appear. Its seems the surface tension of the XTC-3D is exceeding the affinity between the XTC-3D and the surface being coated. Same reason oily spots on a glass surface prevent water from forming a smooth sheet. Or spray paint fails to coat dirty patches.

The answer in all these cases is the same. Clean the surface. Use a cleaner or solvent compatible with the surface being treated. Deodorized mineral spirits (mineral spirits minus toluene and other aromatic hydrocarbons) work well for many surfaces. One possible solution, though I haven't had an opportunity to try it since I heard about it, is to thin the XTC-3D with acetone or denatured alcohol. These should lower the surface tension and increase surface penetration. And of course, use appropriate safety precautions regardless of what you do. At the least, use gloves with epoxy as exposure to it can sensitize resulting in nasty allergic reactions on re-exposure.

I hope this helps! And thanks to those posting on solvent polishing PLA with acetone. I'd always failed with it (and with THF polishing of PLA) but I learned some things I'm going to have to try out with selected brands of PLA.

  • Like 1

Share this post


Link to post
Share on other sites

Hi Edel,

Don't apply it thin, XTC3D works much better when you use it generously, not to much as most will just drip of but give it a good coating. It will dry up very smooth if you do it like that without any holes. My first attempt was also the same as you and then i found a youtube video where they said the same, apply thick or you will get holes. After that i did multiple prints and all look amazing.

Also do it in a warm enviroment, or heat the bottle up in the sink with some warm water to make it much easier to work with.

Hope this helps as it is really a good product.

Greetz Barry

Share this post


Link to post
Share on other sites

Personally I will say follow the instructions and you will not go wrong; that includes measuring very carefully, to the instructions, the volumes you mix together. Interesting comment from @phantom on temperature; I have always applied it in a room with a minimum temp. of 20c.

I wonder what PLA you are using as I have never experienced your problem; I am just wondering if you are using a cheap PLA which is leaving some residue on the finish.

I think this is down to experience to get it right - On my first few attempts I was suffering on runs on non-horizontal surfaces (good finish where it did not run though)so I gradually loaded the brush with less XTC 3D until I got to a point where I did not get runs.

I certainly would not apply any thinner to the mix - not in the instructions! - but how much you load your brush may have an impact and of course is a personal decision, so one man's thin may not be another man's thin.

Also the type and quality of the foam brush will potentially have an impact.

Share this post


Link to post
Share on other sites
I wonder what PLA you are using as I have never experienced your problem; I am just wondering if you are using a cheap PLA which is leaving some residue on the finish.

This may be a bit off topic, but when I build commercial models, I always wash the heck out of my parts. Mold release and all that stuff.

I have carried that over to washing all my printed parts as well. Basic de-greasing/dish soap and just warm enough to not warp the plastic involved. Basically, not cold as that does not help the soap come off, and then a lot of rinsing until the fingers squeak on the material.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Our picks

    • Taking Advantage of DfAM
      This is a statement that’s often made about AM/3DP. I'll focus on the way DfAM can take advantage of some of the unique capabilities that AM and 3DP have to offer. I personally think that the use of AM/3DP for light-weighting is one of it’s most exciting possibilities and one that could play a key part in the sustainability of design and manufacturing in the future.
      • 3 replies
×

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!