Cleaning FUD

[Alex.]

What's the best method at removing the wax residue?

I used white spirit once and the print went frosty white, worried it might have weakened it.

[billbedford]

NEVER use spirit based solvents on FUD. Detergents in an ultrasonic bath is one good way. Don't use enamel paints either.

[AJ427]

I use soapy (washing up liquid) luke warm water and gently rub over with an old soft toothbrush before rinsing and drying thoroughly by dabbing with an old towel or cloth. Model is then primed with an acrylic primer. Seems to work without problems.

[sjgardiner]

Good timing on starting the topic.  I have my first parts ordered in FUD at Shapeways now, and how to paint them and prep them was on my mind.

 

In relation to the question regarding enamel paint, is it a chemical reaction damaging the FUD issue, and if so, would an acrylic primer be sufficient protection for an enamel paint?

[billbedford]

The problem is that the wax support material can get incorporated into the plastic, and Shapeways use a vegetable oil bath to try and dissolve the wax left on the surface. This doesn't always work 100% and there have been reports of pieces painted with enamels which don't dry because they have picked up some of the oil/wax mixture from the model. Personally I don't really understand why anyone would not want to use acrylic paints.

[Tricky-CRS]

I used enamels and the paint never fully set, stayed tacky for over a year. I have used white spirit with no issues on test models that will not need to last long. Best approach is ultrasonic jewelry cleaner on 4-5 cycles of 5 mins each, then spray and then use masking tape to see if any paint lifts off. I use Halfords primer with great results.

[sjgardiner]

The problem is that the wax support material can get incorporated into the plastic, and Shapeways use a vegetable oil bath to try and dissolve the wax left on the surface. This doesn't always work 100% and there have been reports of pieces painted with enamels which don't dry because they have picked up some of the oil/wax mixture from the model. Personally I don't really understand why anyone would not want to use acrylic paints.

 

Primarily availability of paint colours, you'd be surprised how barren and overpriced the paint sections at the model shops in a City the size of Toronto can be sometimes, often the only available paints to get a colour are older stock enamel paints, it can be hit or miss.  As well, for a very small project, buying an overpriced large bottle of acrylic paint vs. a very cheap small bottle of enamel makes the budget go much much further!

[billbedford]

Can't you use artists colours?

[edubs]

I used nail varnish remover containing acetone, and cotton buds, with a good scrub using toothbrush and detergent both before and after.  

 

No damage was caused and  the models took acrylic paint with no apparent problems.

 

There's a thread or two about this subject on the Shapeways forum.

[Etched Pixels]

I've had no problems with white spirit as a cleaner, and you can then  paint directly onto them with enamels. I prefer to clean them with something lighter then use games workshop acrylic primer and do the tape test as well.

 

Given a couple of coats of acrylic primer you can enamel over the top in my experience.

 

Alan

[Dazzler Fan]

Suggestions on Shapeways Forum are a US product called "Bestine" -

sold as a solvent & thinner for "thining and reducing rubber cement" and

produced by Union Rubber Inc, Trenton NJ.

There is a warning about N-Hetane.

 

Company pitch":-

"Formulated for thinning rubber cement, Bestine is also a most versatile cleaner. Bestine readily cleans up inks, spray adhesive, and is an exceptional parts cleaner. Over the years, professionals have used Bestine for removing both decals and labels from all types of surfaces.

But, most important, Bestine does not dissolve most plastics."

 

In the UK:-

Artstat Creative House
Tilson Road
Roundthorn Industrial Estate
Manchester, UK M23 9WR
Roy Swindell
action@artstat.co.uk

Recent items from Shapeways have been remarkably clean, from the days

when there was thick wax in corners.

Acrylic paints go on fine.

 

Noel

[JohnBS]

I tried several methods on the trial prints (Shapeways FUD) for the Saint and 3500 gal tender.

In the end, I used surgical spirit (ethanol), decanting a small quantity in a clean tub, then brushing on repeatedly and rinsing and drying. The spirit in the tub became quite milky so obviously something was coming off the printing. When I was reasonably satisfied that not much more was being lifted, I dried the loco and tender thoroughly and put them in warm water (say 50deg C) with a little washing up liquid in my Lidl ultrasonic cleaner (a bargain for I think 8.99 GBP) for a good brew (10 minutes). Again the liquid became slightly milky. I repeated the clean twice more with fresh warm water, without WU liquid, until there appeared to be no further change. Then all left to dry overnight.

This seemed to work fine; the grey Halford primer adhered well, without rolling off when lightly sanded. My guess is that isopropyl alcohol would do a similar job.

John

[D869]

I've just ordered some IPA on eBay based on the advice here. I don't have an ultrasonic cleaner though so I think it'll be an old toothbrush for me, at least to begin with.

 

The thing that worries me somewhat is that my Bromine tanks arrived from Shapeways not just with a slight coating of wax but with quite big clods of the stuff inside in spite of having quite a sizeable square opening in the bottom. I intend to shift what I can using a toothpick but am concerned about any remaining wax oozing out over time.

 

Should I expect IPA (or any other solvent) to dissolve the wax (which might solve all of my problems) or does it just loosen it to make it easier to shift mechanically or with ultrasound (which won't) ?

 

While googling for Bestine (and finding some sites that seem to be populated by some colourful characters using it for very questionable chemical processes) I found a suggestion to use Naphtha (e.g. Ronsonol) instead as a cleaning solvent, but not specifically for FUD. Unlike Bestine (which I think is Heptane) this seems to be a mix of light oil fractions approximating to low octane petrol but all in the general vicinity of Heptane in terms of molecular weight. Since it is rather more easy to get hold of, does anybody have any thoughts/experience regarding its likelihood to shift the wax and (hopefully not) attack FUD?

 

Regards, Andy

[billbedford]

Most bureaus that run the machines that produce FUD melt out the wax and then wash the pieces in a light oil. Shapeways use a mineral oil, and have used vegetable oils in the past. So, to remove the was trapped inside your tanks, turn them upside down, fill them with either cheap sunflower oil or baby oil and leave them overnight. You will have to give them a good wash with soapy water once the wax has dissolved.

 

I would be very reluctant to use any solvents like heptane of naphtha on FUD. While they will remove all traces of wax they will also produce a rough surface texture where the support wax has been in contact with the plastic.

[D869]

So, to remove the was trapped inside your tanks, turn them upside down, fill them with either cheap sunflower oil or baby oil and leave them overnight. You will have to give them a good wash with soapy water once the wax has dissolved.

 

Certainly worth a try. The things were covered in oil when they got here anyway, so I don't have anything to lose.

 

That brings me to another question though... what kinds of soap can we get hold of that are not likely to contain other paint-repelling substances like lanolin? I suspect the stuff in my bathroom has all kinds of moisturisers and whatever - great for your skin but not so good for a surface being prepared for painting. I'm pretty certain that the green stuff that resides by the kitchen sink contains lanolin too.

 

Regards, Andy

[Dazzler Fan]

Certainly, a final soak in hand hot water with unadulterated washing-up liquid, and judicious use of an

old toothbrush, will give a surface ready for a primer.

 

Some of these solvents are dangerous to breath and get on your skin, so follow instructions carefully.

[D869]

I soaked one of the tanks overnight in an egg cup filled with cooking oil. Checking this morning, the tank still looks very white and I can still see the translucent bits where I managed to shift the wax with a cocktail stick so it certainly hasn't dissolved the wax.

 

I gave it some more prodding with the cocktail stick and I'd say that the oil has softened the wax and is helping it to break up but some areas of wax still seem to be quite hard but that still leaves the problem of shifting the wax (soft or otherwise) from the areas of the inside of the tank that I can't prod.

 

Sometimes I can see a sort of film on top of the oil which may be broken up wax but I can also see what look like lumps of solid wax in the bottom of the egg cup.

 

Anyway I don't have time to do anything further just now so I'll just leave it to soak in the oil for the rest of the day.

[D869]

Some updates...

 

The IPA is still in the post somewhere so the bromine tank has been left soaking in the cooking oil. I decided that the oil was not going to dislodge the wax in my lifetime but it was softening it so periodically I've been giving it a prod with a cocktail stick and various bits of wire to reach around the corners. Some of the wax was seriously hard and was still resisting attempts to shift it after 24 hours of soaking.

 

I think that I have shifted most of the wax now. There is still some residue in the inside corners and also on the part of the tank (inside) where the really hard wax was but I think it is now clean enough to move on with reasonable confidence that the remaining wax residue won't ooze out over time. I've now stuck it in a bath of fresh cooking oil and intend to give it a wash and brush up tomorrow to shift the oil... always assuming I can lay my hands on something that isn't packed with skin moisturising additives... which might still prove tricky to track down in my house.

 

So the oil bath does seem to work, but it takes a heck of a long time and some effort if your print (like mine) has a lot of wax remaining on it.

 

I also ran another experiment with some Ronsonol. I cut a FUD sprue off another print and smeared this with some of the (unsoaked) wax that I originally managed to manually scrape out of the tank. I put this into a tin lid (along with a lump of Plastikard) and then put some Ronsonol in. This unstuck the wax from the sprue in moments and dissolved it completetely after maybe 20 minutes. As a test I left everything alone until the Ronsonol had evaporated. As far as I can tell it has not softened the FUD or the Plastikard but it has turned the FUD white... which seems to be a similar result to reports of people trying white spirit, Bestine etc.

 

So I guess that the place where opinions vary is whether the fact that solvents make the FUD go white is actually evidence of damage or not.

 

Or... on the other hand whether if your FUD has not gone white, does that mean that you haven't shifted all of the wax and oil?

 

My guess is that we won't know unless somebody puts the stuff under a powerful microsocope. All we mere mortals can do is observe whether it goes white or not and then offer our own opinions about whether the whiteness is good or bad.

 

Regards, Andy

[D869]

Still looking for 'pure' detergent. What I have right now is Morrisons savers washing up liquid. The bottle makes no mention of lanolin but it does have...

 

"5-15% Anionic surfactants

Less than 5% Non-ionic surfactants, Amphoteric surfactants, Dimethylol Glycol, Benzisothiazolinone, Laurylamine, Dipropylenediamine, Iodopropynyl Butylcarbamate, Perfume, Limonene"

 

Not exactly 'unadulterated' but I suspect that most other makes will have a bunch of additives too.

 

So I googled this lot...

 

Surfactants - These break down surface tension, which doesn't seem like a bad thing to me

Dimethylol Glycol - antimicrobial apparently - some sort of alcohol so probably OK

Benzisothiazolinone - a 'biocide' (sounds nasty!)

Laurylamine - another surfactant maybe. A 'fatty amine' sometimes a lubricant, so possibly a bad thing for paint?

Dipropylenediamine - no idea what this is for or whether it is likely to be a problem

Iodopropynyl Butylcarbamate - preservative and biocide again

Perfume - could mean anything including oily stuff

Limonene is a solvent (which is also present in Flash).

 

Can anybody add to the above and say whether this stuff is likely to be good or bad?

 

...or else anybody know of a better detergent with less odds and ends mixed in?

 

(meanwhile the print can stay in its oil bath for a while longer)

 

Regards, Andy

[billbedford]

I think you are worrying about this too much. I have never had problem with acrylic primer sticking to FUD after a clean in an ultrasonic bathe of water plus a squirt of washing up liquid.

[D869]

I think you are worrying about this too much.

 

Very probably... although it's more a case of having other stuff to do than procrastinating over cleaning up the tank that's still sat in its oil bath.

 

If I was in a hurry I'd have hit it with a solvent several days ago

 

One of the 'other stuff' items today involved a visit to a pound shop where I found that their cheapo washing up liquid had a similarly long list of additives, so I reckon that the Morrisons stuff is par for the course.

 

Regards, Andy

[Penrhos1920]

Still looking for 'pure' detergent. ..

Regards, Andy

 

They used to call it Sugar Soap which you could get from DIY shops.  Normally used for cleaning old paint before painting wood or walls etc  I've used it to clean models before models, but not FUD yet, before painting.

[andygif]

They used to call it Sugar Soap which you could get from DIY shops.  Normally used for cleaning old paint before painting wood or walls etc  I've used it to clean models before models, but not FUD yet, before painting.

wear gloves tho, sugar soap can be a bit vicous on the skin because its quite alkaline.

[Pete Harvey]

Hi Guys on the subject of cleaning FUD I asked the question of Shapways and received the following response:

 

Hi Peter,

 

Thanks for reaching out to us.

Our FAQ page is currently under construction, we're working hard to update it.

 

You can remove the wax residue by placing the model in a hot water, oil or oven (around 70C degrees, not more!). The oil coating can be removed by simply washing the models in dishwasher soap water (around one teaspoon for 100ml).

If this doesn't remove the oil completely, try adding a bit more soap. Note that adding too much soap will make the model a bit more white and less translucent.

 

I hope this helps. Please let me know if you have any further questions.

 

 

 

Not sure if I want to try the oven but I will try the hot water.

 

Pete

[alibuchan]

Water hot enough to wash your hands in (approx 50 deg) and a squirt of fairy liquid seemed to work quite well in an ultrasonic bath. Cleaned my bits up in 2 x 8 minute cycles with fresh water each time. Came up lovely.

 

Alistair