What’s your undercoating preference?

homechild

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Just wanted to get the opinion of the experts here on undercoating.
I’m assuming the colour used would be dependent on what the final model colour scheme is going to be (lighter undercoat for lighter coloured models, etc) but is your preference to undercoat while still attached to the sprues or not?
 

Jim R

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Hi Gary
I rarely undercoat/prime/paint on the sprue for a couple of reasons. Firstly I need the part to be cleaned up and dry fitted before priming. Secondly I like to do the same as Gary and put together as much as possible before priming.
I use Stynylrez Primer. Black. white or grey depending on the final colour.
Jim
 

Murfie

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I've used many different acrylic primers in the past ... Tamiya, Humbrol, Vallejo, Gunze for example. At the moment I am using Ammo grey One-Shot primer and am very happy with its performance. I use it to prime internal parts/areas of the model on the sprue with an airbrush which saves a lot of time. Externals are airbrushed prior to first finishing coat. Retention of fine detail is exceptional. While I mainly use the grey primer, I do have bottles of both white and clear should the next coat be better served with them underneath, as red, yellow and orange do not go on well over darkish grey.
 

Tim Marlow

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I have never painted parts on the sprue, and like Jim and Gary, I like to dry fit parts, and paint sub assemblies Etc first. As to primer colour, depends on the final colour. Figures I almost always prime in grey, but tanks and planes can be primed several colours From black to white via sand and red oxide depending on the final finish. Mostly though I use grey......it’s a good neutral for any top colour, and Tamiya grey goes on great through and airbrush.
 

homechild

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Thanks for the replies so far (keep them coming).
I used to undercoat on the sprue but realised you might have to clean the part before fitting.
Also, I’ve been using the Tamiya spray can undercoats and, while it might be good for larger, less detailed surfaces, I found it to be a bit too much for the likes of modern fighter jets.
 

Tim Marlow

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I always decant out the Tamiya spray From the can and then dilute with Mr Color levelling thinner to use it through my airbrush. Goes on as fine as you like then.....
 

Defiant911

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I have been using vallejo primers for the last few models and although it’s quite thin straight out of the bottle I found like most paints it dries the tip of the airbrush unless you add some thinners and mix it slightly. this was causing me a real headache until I realised just thinning the paints or primers lets it flow lovely with hardly the need to clean dry tips at all. I guess all these things can be trial and error and I’m doing plenty of that.
 

Dave Ward

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I undercoat assemblies, as far as possible - mostly I use a neutral grey, I'm using AK primer at the moment....................
If the final finish is going to be a white, or red, then I do use the appropriate colour primer - it saves going over, and over to cover a dark primer.. One primer I won't touch ( anymore ) is Vallejo Grey Primer, I have had endless trouble with this through several airbrushes - tried different pressures & mixes, but no go. I now use it to brush prime smaller parts ( well, I wasn't going to throw it away! ).
Dave
 

Jakko

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I often don’t undercoat at all — I generally only do that if the model contains resin and/or metal parts, not if it’s all plastic unless that’s very dark and I want a light-coloured finish. When I do undercoat, it’s usually with a spraying can of primer sold for modellers or wargamers (my current one is Vallejo, but I’ve also used Games Workshop and Army Painter in recent years).
 

homechild

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I often don’t undercoat at all — I generally only do that if the model contains resin and/or metal parts, not if it’s all plastic unless that’s very dark and I want a light-coloured finish.
Well!
I suspect you’ll be in the minority with not undercoating models (except in those circumstances).
 

Paintguy

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~but is your preference to undercoat while still attached to the sprues or not?
Mostly not, as like Jim I like to know the part is cleaned up and will fit before splashing anything on it.

There have been several times with really small parts that I've kind of done them on the sprue though, especially if they are going to be a different colour to what they will be mounted to. I say kind of on the sprue as I'll snip them out as much as I can, leaving one attachment point and a bit of sprue as something to hold it with for priming & painting. I can then clean most of the part, just leaving one bit that'll need touching up later.

Like some of these.

 

Allen Dewire

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Hi Drew,

I don't undercoat either......Mr. Metal Primer for etch and I wash my resin before adding it. Then I spray or brush my color on the model and that's it. So, Like Jakko, guess I'm in the minority too...……….

Bleib Gesund
Allen
 

Bobthestug

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Like Dave i use to use Vallejo surface, but after a while had issues with thinning and blockages.

I now tend to use Mr Surfacer, black or grey thinned 50/50 or halfords plastic primer
 

Jakko

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I suspect you’ll be in the minority
Story of my life :smiling3:

with not undercoating models (except in those circumstances).
Oh, you meant in this regard! ;) I see undercoating as a way to either make the “real” layers of paint adhere better, or to prevent colour differences in them (or both). Since most model paints adhere perfectly well to plastic, I feel there’s no need to add an extra layer of paint under them unless it’s to provide an even or light colour underneath. Acrylic model paints adhere poorly to resin and especially metal, though, so those need a primer that does adhere well.
 

beowulf

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i must be the odd one out here lol

i use cheap rattle can automotive primer (tried all sorts of 'modelling' primer......got a big expensive bottle of AK One Shot primer.....worst ive ever used...always go back to rattle can stuff...cheap and easy to use)......tend to use grey or white mostly, whatever is a contrast to the styrenes colour
i make up small sub assemblies like engines or fuel tanks which get primed as is but i tend to give the sprues a light prime.
i think a lot of it depends on what you are building...i can see the point on an aircraft where fuselage and wing root seams need to show up but i do a lot of bikes where i tend to paint a lot of small parts then build just as if it was the real thing
 

yak face

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i must be the odd one out here lol

i use cheap rattle can automotive primer (tried all sorts of 'modelling' primer......got a big expensive bottle of AK One Shot primer.....worst ive ever used...always go back to rattle can stuff...cheap and easy to use)......tend to use grey or white mostly, whatever is a contrast to the styrenes colour
i make up small sub assemblies like engines or fuel tanks which get primed as is but i tend to give the sprues a light prime.
i think a lot of it depends on what you are building...i can see the point on an aircraft where fuselage and wing root seams need to show up but i do a lot of bikes where i tend to paint a lot of small parts then build just as if it was the real thing
Not quite Paul , I use Halfords grey primer or Halfords white primer blasted straight out of the can or if I want to black base then I’ve got some UMP ( stynylrez) for the airbrush . I find the Halfords grey gives a lovely finish , shows up any areas that need further attention and definitely helps the top coat to stick , I’d say I use this 75% of the time . The white is handy if the model has any white or yellow parts on it .
 

SimonT

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I never paint anything on the sprue

I usually prime to give a good uniform surface - my builds generally have a mix of plastic, pewter, aluminium, copper, etch brass, resin, filler

It often shows up defects allowing them to be rectified before spraying top coat

I normally use white Halfords 500ml car primer as I like the finish it gives and their cans tend to spray nicely, unlike some car paints that sputter all over the place - like Tony, I spray it straight from the can

I then tend to cover that with a quick blast of black MIG Ammo OneShot as a base coat before starting the top coats
 
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