Which primer, if any ?

Hi everyone,


I'm just getting back into modelling after a gap of nearly sixty years (!) and am wondering about primers.


I've just ordered my first Iwata Eclipse HP-CS airbrush and the Iwata Power Jet PRO compressor and can't wait to try them out and practice, practice, practice.


My questions are twofold, as follows:-

1. For top coats in acrylic paint, that is, initially Humbrol for my first project but then thereafter Tamiya, what primer would you recommend, please? And

2. For re-chroming the odd piece in Alclad II, I assume a good primer would be their Alclad II Grey Primer and Filler. Would this perhaps also be a good primer to work with acrylic top coats?

I'd much appreciate your thoughts on this.


Regards,


Graham.

I don't use a primer I just wash the kit in warm soapy water and leave it to dry , the idea of primer is to make your top coats key to it but primer is essentially the same type of paint so what makes the key to the surface ?


I've never had any problems with not using a primer choice is yours and you will lots of advice on it from the good folk on here

That's a great new purchase you've made there, you will find the air brush invaluable. As for paints I am a humbrol enamels man so I can't really help you there(I've never got on with acrylics) I use Halford car primer (the plastics one) and for chrome parts I use polishing powders.

\ said:

I don't use a primer I just wash the kit in warm soapy water and leave it to dry , the idea of primer is to make your top coats key to it but primer is essentially the same type of paint so what makes the key to the surface ?
I've never had any problems with not using a primer choice is yours and you will lots of advice on it from the good folk on here

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Hi Alan,


Thanks for that. Appreciate your views. I must admit I don't remember needing to use a primer in the 'olden days', but much has changed no doubt and I just want to be sure rather than blunder ahead -- although I'll probably be doing lots of blundering anyway :D ...


Regards,


Graham.

\ said:

That's a great new purchase you've made there, you will find the air brush invaluable. As for paints I am a humbrol enamels man so I can't really help you there(I've never got on with acrylics) I use Halford car primer (the plastics one) and for chrome parts I use polishing powders.

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Hi Ken,


Yeah, Halfords is a bit outa my range here in France, although French automotive shops will almost certainly sell something similar.


As to colour of primer, would you recommend a light grey perhaps, a mid-grey or what about white to enhance the top coat?


Your thoughts would be much appreciated.


Regards,


Graham.

Depends on colour you are spraying and the colour of the plastic you are covering. If the plastic is dark and it needs a light colour to cover it I always use a primer to cover the colour of plastic.


The lighter coloured plastics can just be lightly sanded with very fine wet and dry cleaned then sprayed

\ said:

Depends on colour you are spraying and the colour of the plastic you are covering. If the plastic is dark and it needs a light colour to cover it I always use a primer to cover the colour of plastic.
The lighter coloured plastics can just be lightly sanded with very fine wet and dry cleaned then sprayed

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Hi Paul,


So again, not really any need for primer, unless the shade of plastic diverges so horrendously from the target top coat colour, when I could see the need perhaps...


Many thanks for that Paul.


Regards,


Graham.

\ said:

Hi Alan,
Thanks for that. Appreciate your views. I must admit I don't remember needing to use a primer in the 'olden days', but much has changed no doubt and I just want to be sure rather than blunder ahead -- although I'll probably be doing lots of blundering anyway :D ...


Regards,


Graham.

Click to expand...

Just giving you an option, in my experience there's no right or wrong in using primers it's whatever your happy with give them both a try and see what you prefer but always remember to wash the kit or paint won't stick :D

In my opinion primer is essential especially if you are using the primer that is by the manufacturer of the finishing paint. I am talking essentially here water based acrylics.


Primer will hold firmer onto plastic than the top coat. Found evidence of this when painting figures ie pilots etc.


If I paint a figure with a top coat for one colour and then handle the figure, after curing of the first colour, the first colour will deteriorate.


Bizarrely this can help in producing shading, by accident, in rubbing off of parts of the first coat.


But for general use you do not want your top coat to be degraded when handling.


Another very good reason for priming is to find any points missed in filling blemishes not obvious in the plastics virginal state.


Not sure of other water based primers but Vallejo have certainly different mixtures to their primers compared to their top coats plus the primer is slightly thicker than the top coats.


Plastics are not the best for adhering to acrylics or perhaps visa versa. They do not adhere well to the plastics. What the primer does is to form a plastic coat around the plastic, with a certain amount of adhesion, and why it is essential, in my view, to use a primer as detailed above.


Also recommend as essential, again water based acrylics, to abrade the plastic to obtain maximum possible adhesion plastic to primer. I have found the best way is to use 1200 to 1500 grade wet and dry paper with water. Making sure the plastic is washed before priming.


Tamiya is not waterbased and I do not have any experience with this paint .


Laurie

Dear Laurie,


Thank you SO much for your very full and complete reply. It's super to be getting so wider a range of such diversified views from such very experienced modellers. On balance, I am inclined to err on the side of caution and therefore use a primer... As suggested, I can always try both methods, with and without, and compare to see which I like best.


Thanks again for giving my question a good deal of thought.


Kind regards,


Graham.

Just add Graham that with a primer it does help as it is a little thicker than the top coat to wet and dry (with water) to get a good smooth base coat for the top coats.


Also what I did miss especially for the bigger parts of the model.


This is to give a mist coat of primer, thinned 25%, this gives a shorter drying time which helps to get a closer contact and adherence to the plastic.


Then a final full coat of primer. all takes a little longer but it is worth it.


Basically I am using Vallejo primer as an example. A plus with Vallejo is that they do about 10 different colour primers plus they are produced specifically for airbrushing.


If you do use Vallejo I would recommend their Flow improver which I have found transforms airbrushing with water based acrylics.


If you mask up for various reasons camouflage etc with a primer you stand a better chance in not stripping the paint. Bitter experience has proved that one.


Make sure you cure the primer 24 hours at least before wet and drying more time if your are patient !


Laurie

I too like a primer, for the reasons mentioned above. It definitely helps to show up flaws. Take a look at these pictures of some major surgery (complete new tail) on one of my recent builds.


Great care was taken when removing the kit tail to make sure the cut would align with the new resin part:


View attachment 113421



This was eventually glued in place, filled and sanded before primer was applied. I too use Halfords plastic primer, others are available:


View attachment 113422



You can see that the primer has revealed some minor flaws which can be easily fixed at this stage. If discovered at the final painting stage this would be much more of a nuisance. After remedial work, a bit of re-scribing of panel lines and re-application of rivets the join is invisible on the finished model:


View attachment 113423



Grey primer is good for most applications. I use white under white, yellow or red as these often don't cover well. Under some specialist metallic finishes, particularly highly polished finishes a gloss black primer may be required as on this ancient kit I attempted to resurrect a couple of years ago:


View attachment 113424



I use enamel paints which supposedly adhere better to plastic than most acrylics. I still find a primer useful.


Cheers


Steve

\ said:

Just add Graham that with a primer it does help as it is a little thicker than the top coat to wet and dry (with water) to get a good smooth base coat for the top coats.
Also what I did miss especially for the bigger parts of the model.


This is to give a mist coat of primer, thinned 25%, this gives a shorter drying time which helps to get a closer contact and adherence to the plastic.


Then a final full coat of primer. all takes a little longer but it is worth it.


Basically I am using Vallejo primer as an example. A plus with Vallejo is that they do about 10 different colour primers plus they are produced specifically for airbrushing.


If you do use Vallejo I would recommend their Flow improver which I have found transforms airbrushing with water based acrylics.


If you mask up for various reasons camouflage etc with a primer you stand a better chance in not stripping the paint. Bitter experience has proved that one.


Make sure you cure the primer 24 hours at least before wet and drying more time if your are patient !


Laurie

Click to expand...

Hi Graham


I am new back into modelling after over 20 years, I didn't exactly do it to a high level then as I was young and had little guidance/help.


If your new to this forum and you find yourself a little lost with changes that may have happened in the last 60 years, you'll get all the help you need here the guys are great, so welcome.


I agree with Laurie here, it's not that the paint won't adhere straight to the model without primer because it probably will, it's more the fact that it just won't be as hardy. When I painted my first plane by the end of the finishing I.e decals and added details I noticed some of the paint had worn, I expect it would have been a lot worse if I hadn't of primed it.


I don't get a lot of time to build so picking it up and putting it down between painting and varnishing over a couple of weeks will damage paint, I suppose it depends how much time you have to build. I'm just starting out but I do have a little understanding of paint processes, also if you put say for example a light blue direct on a dark green styrene model it will undoubtedly dry with a different hue to going direct onto a white styrene model unless of course you lay it on thick then running the risk of loosing detail, so why not try a light primer first I will always probably stick to light grey.


I also mainly use Vallejo primer and model air colours in a similar way to Laurie they are fantastic. I use daler Rowney acrylic flow enhancer and that works a treat, I have just purchased some Vallejo thinners for acrylic but am yet to try.


Kind regards


Phil

\ said:

I too like a primer, for the reasons mentioned above. It definitely helps to show up flaws. Take a look at these pictures of some major surgery (complete new tail) on one of my recent builds.
Great care was taken when removing the kit tail to make sure the cut would align with the new resin part:


View attachment 124473


This was eventually glued in place, filled and sanded before primer was applied. I too use Halfords plastic primer, others are available:


View attachment 124474


You can see that the primer has revealed some minor flaws which can be easily fixed at this stage. If discovered at the final painting stage this would be much more of a nuisance. After remedial work, a bit of re-scribing of panel lines and re-application of rivets the join is invisible on the finished model:


View attachment 124475


Grey primer is good for most applications. I use white under white, yellow or red as these often don't cover well. Under some specialist metallic finishes, particularly highly polished finishes a gloss black primer may be required as on this ancient kit I attempted to resurrect a couple of years ago:


View attachment 124476


I use enamel paints which supposedly adhere better to plastic than most acrylics. I still find a primer useful.


Cheers


Steve

Click to expand...

Yep, forgot to mention that! Primer is key for showing big indescrepencies as well as covering small ones before final painting, good points Steve.


I use the same light grey Vallejo primer before alclad II and had no probs although as Steve said I believe for some nmf, black of gloss black primers will be needed.

\ said:

I too like a primer, for the reasons mentioned above. It definitely helps to show up flaws. Take a look at these pictures of some major surgery (complete new tail) on one of my recent builds.
Great care was taken when removing the kit tail to make sure the cut would align with the new resin part:


View attachment 124473


This was eventually glued in place, filled and sanded before primer was applied. I too use Halfords plastic primer, others are available:


View attachment 124474


You can see that the primer has revealed some minor flaws which can be easily fixed at this stage. If discovered at the final painting stage this would be much more of a nuisance. After remedial work, a bit of re-scribing of panel lines and re-application of rivets the join is invisible on the finished model:


View attachment 124475


Grey primer is good for most applications. I use white under white, yellow or red as these often don't cover well. Under some specialist metallic finishes, particularly highly polished finishes a gloss black primer may be required as on this ancient kit I attempted to resurrect a couple of years ago:


View attachment 124476


I use enamel paints which supposedly adhere better to plastic than most acrylics. I still find a primer useful.


Cheers


Steve

Click to expand...

Dear Steve,


Most grateful, as ever... I've really learned a lot from your views and the series of photos on that repair. Just incredible what can be achieved. Like you say, the minor surface anomalies show up well at an early stage... Brilliant job!


Thanks once again for your much valued advice.


Best regards,


Graham.

\ said:

I'm just getting back into modelling after a gap of nearly sixty years (!) and am wondering about primers.

Click to expand...

Gee Graham just picked up on this. Welcome with a bit of luck you will be older than I am and take away the stigma from me of being (I think) the eldest participating member here.


I hardly like to ask your age as I may well be so disappointed ( not really just good fun).


Laurie

\ said:

Hi Graham
I am new back into modelling after over 20 years, I didn't exactly do it to a high level then as I was young and had little guidance/help.


If your new to this forum and you find yourself a little lost with changes that may have happened in the last 60 years, you'll get all the help you need here the guys are great, so welcome.


I agree with Laurie here, it's not that the paint won't adhere straight to the model without primer because it probably will, it's more the fact that it just won't be as hardy. When I painted my first plane by the end of the finishing I.e decals and added details I noticed some of the paint had worn, I expect it would have been a lot worse if I hadn't of primed it.


I don't get a lot of time to build so picking it up and putting it down between painting and varnishing over a couple of weeks will damage paint, I suppose it depends how much time you have to build. I'm just starting out but I do have a little understanding of paint processes, also if you put say for example a light blue direct on a dark green styrene model it will undoubtedly dry with a different hue to going direct onto a white styrene model unless of course you lay it on thick then running the risk of loosing detail, so why not try a light primer first I will always probably stick to light grey.


I also mainly use Vallejo primer and model air colours in a similar way to Laurie they are fantastic. I use daler Rowney acrylic flow enhancer and that works a treat, I have just purchased some Vallejo thinners for acrylic but am yet to try.


Kind regards


Phil

Click to expand...

Hi Phil,


Many thanks for your considered views on the subject of priming, which I'm coming to realise represents that extra mile that one needs to go in order to achieve the best possible paint finish. As they say in DIY, it's all in the preparation and I now believe priming in model building is well advised.


Thank you, Phil, for getting in touch and for your sound advice, which will stand me in good stead for the future, I'm sure.


Kind regards,


Graham.

\ said:

Gee Graham just picked up on this. Welcome with a bit of luck you will be older than I am and take away the stigma from me of being (I think) the eldest participating member here.
I hardly like to ask your age as I may well be so disappointed ( not really just good fun).


Laurie

Click to expand...

Wether you like it or not I don't think your gonna shake off that stigma Laurie


Your right Graham, that is something I'm always saying in life and not just for DIY, " it's all about the prep"

\ said:

Wether you like it or not I don't think your gonna shake off that stigma Laurie

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To "quote" Winston S Churchill : “Nothing in life is so exhilarating as to be shot at without result.”


Laurie

Forgotten another prime reason for priming.


Acrylics tend, except for black and those near on the spectrum, to be slightly translucent especially when you approach the opposite end of the spectrum white yellows etc.


Also airbrushing work is gives a paint covering which is quite thin. This is used by some as a technique to pre-shade.


During preparation of the model for painting there is inevitably some filling work (especially on a Revell Longbow Apache) and also trimming of plastic.


Covering this with neat top coat does not in most cases stop the whitish filling grinning through the paintwork.


Priming will, being virtually opaque, cover the filler and also where trimming has occurred.


Laurie