Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Painting, Finishing and Care. => Topic started by: Hande on April 22, 2016, 06:49:11 pm
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I have done some homework and found already that for brass I want etching primer (whatever that is in Finnish...).
But out of curiosity, what is WRONG here. I'm apprehensive about painting and this scares the guts out of me:
I used Vallejo primer "suitable for brass" (among other). After 20 hours of curing, gentle rubbing with a kitchen towel took it away - no trace left...
Getting desperate already - and this is my first paint job on my build.
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I have always used an etch primer when I use paint on brass, I didn't think that Vallejo was strong enough to be used on something like a propeller- its too soft even when cured.
To be honest I have never painted any of my propellers leaving them natural-either brass or bronze.
One question: Do you really need to paint your props? If you do then I suggest find some etch primer and go from there, but not many models I've seen have them painted.
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Short of powder coating, very little is going to stay on a prop for long.
Simon
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I see - :((
Thinking back - Without giving the matter much thought I thinned the Vallejo polyurethan "surface primer" with Vallejo acrylic resin thinner. I wonder if they are a match..? I just took it the same way I have practiced thinning the proper paints.
Props could be left unpainted, true.
However, there are other parts provided in the kit that are brass and have to be painted.
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I've painted my brass on Sovereign with just enamel paint and its not peeled off yet - mind you its not been on the water for some time. Planing to use a primer like Halfords or would just any Humbrol / Revell primer be OK?.
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Photo etched components have been in use for many years and should not pose a painting problem with proper preparation but as Captain Fizz says, painting a polished brass prop that is going to be rotating at several thousand RPM is asking rather a lot!
However, brass does tend to tarnish after a while which takes a lot of the shine off if that is the look you want. There are chemicals which can help the process along, somebody will be able to suggest something.
Colin
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You could use something like Hammerite which normally sticks like....................but you'd have to use their Special Metals Primer which is probably an etch primer anyway.
That said, wouldn't the paint effect the efficiency of the prop?
:o
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Photo etched components have been in use for many years and should not pose a painting problem with proper preparation but as Captain Fizz says, painting a polished brass prop that is going to be rotating at several thousand RPM is asking rather a lot!
Colin
The props aren't polished anymore. I sanded them well to make them have tooth for the primer.
I'm building a tug with geared down motors. Not that fast I guess...
Maybe I should just have thinned the primer with water. I may have created synthetic rubber with the acrylic resin?
I'm going to get etching primer tomorrow for the winch drums and other fittings and think about the props a little more. In many pictures of models, the props are actually painted. Maybe they are painted once a year?
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Hi Hande see pm to you.I use Phoenix Precision Paints brass etch primer.It can be applied by brush best results are obtained by spraying. Allow the primer to dry then apply the paint finish. Contact Phonenix for more information hope this helps good luck.
Stan.
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Thank you (got the PM, too) :-)
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I found quite comprehensive advice by Phoenix Precision Paints.
The stuff they are suggesting for cleaning before applying is scary, though
Etch primer seems to be the best solution. There are two types: single pack and two-pack. Don't buy single pack, unless there is a best-before-date marked on the package and that date is still ahead of you. The acids evaporate within a year from manufacture (not sale).
I continued my research on Vallejo Surface Primer. Apparently, it is NOT TO BE DILUTED at all. Thinning is exactly the method of creating that rubbery goo that I managed to create.
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I found quite comprehensive advice by Phoenix Precision Paints.
The stuff they are suggesting for cleaning before applying is scary, though...
Etch primer seems to be the best solution. There are two types: single pack and two-pack. Don't buy single pack, unless there is a best-before-date marked on the package and that date is still ahead of you. The acids evaporate within a year from manufacture (not sale).
I continued my research on Vallejo Surface Primer. Apparently, it is NOT TO BE DILUTED at all. Thinning is exactly the method of creating that rubbery goo that I managed to create.
Your local Fixus should be able to supply you with a can of U-Pol Acid etch primer.... Not cheap but sticks like poo to the proverbial blanket
http://www.fixusnet.fi/fin/happopohjamaali_harmaa_u_pol-p-623134-0/
You can probably find it cheaper elsewhere
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"Happopohjamaali" - now, there's a mouthful even for a Finn %% I have never heard that word...
Thanks E2V :-))
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As with all metals and NO lets not go to the old debarkle of it works for me,in fact you do NEED to etch prime all metals.
A
Halfords sell U pol etch primer ....it is like water and you wont loose detail.
Right reason for etch primer is simple....it promotes adhesion.
Dave
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Hande.......I understand you have questioned primer on brass, however specifically intend such use on a propeller
This itself is questionable for scale :o....would a bath of copper sulphate + blackening chemical not provide a lifelike greenish surface similar to bronze that has been immersed in salt water?
The other issue for a propeller is aeration/cavitation or and sand in the water........all of which will tend to <*< remove any painted surface............... Derek
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Just wondering if you have tried a 2 part epoxy paint ?
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2 part epoxy, assuming that it works, would be a VERY expensive option unless you happen to have some lying around.
A friend of mine had his props sandblasted to dull them down. He said it worked well.
Colin
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£12 / 250 ml , Border Paints Shrewsbury.
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That sounds interesting Fubar, I'm only familiar with the boat 2 part epoxies which tend to come in at around £35. Is there a direct link as I couldn't see it on the Border Paints website?
Colin
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Dave
Is the U-Pol product the one sold as 'Acid #8 Etch Primer' @ £20 a can?
DM
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Dave
Is the U-Pol product the one sold as 'Acid #8 Etch Primer' @ £20 a can?
DM
That's the stuff!
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@Colin,
Try adding Automotive into the name provided and give them a ring !
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I found the website OK but can't see a reference to two part epoxy in the paint section, just the usual two part colour/clear coat combinations. I don't actually want to buy any at the moment but availability could be useful for future reference.
Colin
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Epoxy is overkill I think.
If you want a cheap and cheerful solution, get a cup of vinegar, enough to immerse the prop in, get some vinegar and add a spoon or two of salt. Protect the thread of the prop boss by blanking off with candle wax, and immerse the prop until it loses all its shine. Rinse off then prime with a normal primer. Should stay put.
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....would a bath of copper sulphate + blackening chemical not provide a lifelike greenish surface similar to bronze that has been immersed in salt water?
.. Derek
Thanks, Derek, for the idea! If the paint comes off, I could attempt that in future. What is an example of a blackening chemical? I'm ignorant and slightly phobic of chemicals in general, and painting inparticular :embarrassed:
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Hande,
Why bother?
A few times on the lake and the props will look perfect.
They will corrode naturally.
Real ones get a jet wash at each docking and if they
are lucky a polish with a wire brush.
Ned
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I guess it's true, Ned.
However, this exercise serves as a learning lesson, too.
Lessons learned:
- there is no universal truth about the matter (I was hoping for one)
- some techniques can be outright wrong - be aware and research for advice
- some fundamentals have to be learned, no matter what
- most of the ideas about painting props are in vain, as the paint will probably fall off
- somehow, I must learn to paint in thin coats - it's diffcult for me {:-{
plus I had the possibility to postpone the painting of the actual build.
It's like the white paper syndrome of a writer :embarrassed:
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I will report on my experiment to the (bitter?) end, for the enjoyment (?) of those that are interested.
I got the U-Pol Acid#8 (Thanks again E2V!) etch primer.
Sanded.
Degreased.
Primed the props and their hubs with the spray can.
Primed portholes and bollards and drop stoppers by brush.
The portholes were glued on already, so I couldn't sand them (or wouldn't, rather).
The drop stoppers above the doors are of copper. They were sanded, but still the primer didn't adhere well. Maybe, when the etching kicks in it does.
I learned from the source that Stan posted (thanks, Stan!) that etching will happen after the primer has dried. Although the instructions of the product that I use say that curing will take place in less than 20 minutes, i found it takes longer than that. I may have had unnecessarily thick coats (according to instructions, 2 coats would be ok). But indeed, when dried, the primer has stuck pretty well.
The primer seems to stick :} O0
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I don't know if you have underfloor heating in your wet room, but I find it a great place to dry painted parts
Just make sure no one takes a shower
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I have an always-on sauna - mildly warm all the time (I open the kiuas, when we actually go to sauna). That's good, too :-)) {-) O0
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%)......... Black Patina brew........... Derek
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How very interesting O0
The patina techniques take the discussion to a new direction.
Patina doesn't fall off, for sure. It may change?
Are they widely used among model builders ?
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This is where I stop painting the props and the rudders until I get to sailing.
The second picture should show the bronzy shade that I created by mixing bronze metal and boltgun metal together.
The anchors got the same colour, except for the varnish being semi-matt, instead of glossy.
We'll see, if the paint holds ...
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That is a lovely colour.... I'm guessing you're using Games Workshop acrylics judging by the names
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It's all Vallejo. I figure as long as I stick to one brand, it's all compatible.
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Correction: it's Vallejo "Gunmetal".
"Boltgun metal" is a Warhammer paint, of course. Very much the same colour.