Author Topic: Mismatch paint types  (Read 11206 times)

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Speedy

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Mismatch paint types
« on: 27 March 2012, 21:33:02 »
HELP......I used Plasticote primer and then a Halfords car spray and the whole damn lot has bubbled and flaked, does anyone know an easy way to strip it all back without hours and hours of sanding??

Offline Manxman1831

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Re: Mismatch paint types
« Reply #1 on: 28 March 2012, 02:02:02 »
If you can - assuming you haven't just spent hours fixing bits in place - get a bottle of Fairy Power Spray, a large see-through bag or bin liner.  Spray the hull thoroughly inside the bag.  Tie the end once, and put it in an airing cupboard for about 24 hours.  If it's a large hull your dealing with, you'll need to wash the hull under a shower set to about midway on the temperature dial, or if it's a small one the kitchen/bathroom sink should do, to wash off the 'gunk'.

This will not get all of the paint off first time, and may have to be repeated a couple of times, but any further deposits left behind will be easily dealt with using a craft knife whilst the surface is still damp and being rinsed off.  Have a scrubbing brush of some kind to hand (old toothbrush or larger if needs be) to assist the paint in coming away from the hull.

This technique has worked for me with plastic kits, and while it does score the plastic slightly (only noticeable on certain lighting), the overall result is better than sanding back.

Do remember to wash the hull extremely thoroughly afterwards to ensure any Fairy spray is rinsed off.  It will interfere with any paint you try to apply if left on.  Trust me, experience is a great teacher, but best to listen to someone else's experience than find out yourself and have to start again.

andy quick

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Re: Mismatch paint types
« Reply #2 on: 28 March 2012, 11:14:29 »
Sounds a good idead for the future but on this job I have completed the aft section of the SOLEBAY complete with guns, lockers and all the paraphanailia.

I thought if I primed it all with a spray of Plasticote primer I could then apply the Car paint, then do the details but its all gone to rats

I am well  ********* off with myself and want to chuck the whole lot in the bin, but I have spent too  much time and money on it so am thinking now to just try to overspray and overspray again to cover everything up.

Offline Manxman1831

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Re: Mismatch paint types
« Reply #3 on: 28 March 2012, 15:26:45 »
Don't go for overspraying, and certainly not with the combination you were going to use.  Sorry if that sounds a bit bullish.  My reasoning is that you have as you said spent hours and money on it.  The job can be rescued.

Use the power spray on a section at a time and clean off the old paint job.  I know that this will more than likely take a long time - a week maybe more to get back to the base materials.

If you intend using the Plasticote primer, presumably the same stuff you can buy from B&Q, then use the paints in their range.  Not many paints are as 'forgiving' as Humbrol, Tamiya and Testors when it comes to mixing them, as you have found out.  Halfords do have their own plastic primer, and metal primer, but I don't think they have a general purpose one, but if they do, then would be the time to use their paints range with their primer.

I have seen the Solebay modelled numerous times, in magazines, at shows and on here, so I'm going to assume that when you describe your build as having most of the stern paraphinalia on it, you have all bar the railings onboard?  Patience is going to be the one thing you will need plenty of.  If you can, remove as many of the larger fittings as you can in order to clean them.  Superstructure can be left on as I assume you've made it a fixed part of the build?

I had a similar experience with a couple of my models a few years ago, and it did take time, but the results of slowly recovering the job are worth the effort.  It will be hard, but don't get downhearted.

Offline mikearace

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Re: Mismatch paint types
« Reply #4 on: 28 March 2012, 19:41:06 »
I feel for you, not that helps much.  I once used plasticote primer as it was on offer as a great buy.  Used it to spray my MS Vliestrom.  It wasnt oversprayed with anything and I was intending to spray over with plasticote satin black but the primer immediately started to bubble and flake a few days after spraying.  The hull had been washed before and rinsed, lightly sanded and prepared but it totally messed up my hull.  I know some people who have used it and say its good but to me now it is horrible nasty stuff to be avoided whether used on its own or in combination.  Halfords cant be beaten in my view for quality or value for money.  The actual grey may not be exactly in line with the chips of official MOD grey but its close enough grey for my purposes!!   

As manxman said it can be rescued.  It just needs time and patience and effort.  Not a job I would like to do though again.

Offline karlgalster

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Re: Mismatch paint types
« Reply #5 on: 29 March 2012, 18:07:04 »
Yes that is hard luck with the Plasticote primer. I use to use Halford's primers but I now use Simonize bought via e-Bay as they seem to do the job fine and much cheaper than Halfords whose prices are much too high for us poor model boaters >:D
In the past I used plasticote satin varnish aersol cans for finishing my first boat. Never again, although the finsh looked great I discovered that it did not key at all well to the underlying Halfords matt black or Halfords red oxide primer. Whenever the boat had a minor knock the varnish became unstuck from the underlying paint and became opaque white looking awful. had to strip all the varnish off and re-varnish with something better. Not much of a problem really as dabbing the varnish with strips of d.i.y. masking tape took it off a treat. ;D
Robin

Offline Caledonia

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Re: Mismatch paint types
« Reply #6 on: 31 March 2012, 21:29:10 »
Oh ,I am approaching priming my Muirneag Model, the cal mac ferry.  Deans advice is to use Humbrol and they have given all the colour numbers etc.

Should I be looking at using something else?Sounds like Plasticote (which I use successfully for house maintenance) is out?

Alex

Offline Manxman1831

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Re: Mismatch paint types
« Reply #7 on: 31 March 2012, 23:02:54 »
I wouldn't count anything out.  As with all things, if it is new to you, test it first - though with the price of paints these days that's not always a cheap option.  Go with what you know.  If you know that Humbrol's work for you, stick with them.

Offline Caledonia

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Re: Mismatch paint types
« Reply #8 on: 01 April 2012, 10:48:48 »
I've no experience painting this type of material so after reading the above thought best to ask around.
For sure after reading this I will do a big test piece first on the surplus plastic left from cutting.

Alex

Offline John Davies

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Re: Mismatch paint types
« Reply #9 on: 22 May 2012, 19:18:53 »
Brake fluid will remove most paints from GRP and plastic quite effectively without eating holes in them, but I'm not sure what the toxicity/pollution implications are of disposing of the remains. Can't be worse than used Nitromors.... but don't use THAT on plastic or GRP!

I've used various aerosols, most of which I would now not touch with a long stick. There is one widely-available brand which even goes crackle-finish if it is applied over a second coat of itself if you get the timings wrong. Okay if the first coat has not begun to cure and is still flexible, okay if the first coat has really set hard, but if the first coat is "half-cured", the second coat drying out above and shrinking ever-so-slightly in the process it will pull everything into a nasty crackle. So there is a period of between an hour and 24 hours after the first coat when you can't do anything. Also, even if the instructions are followed carefully, this stuff can still go wrong. Avoid.

Halfords car touch-up paints are good. Nice weatherproof finish, go on easily, designed to be used by amateurs, easy to use, generally problem-free. They will strip a variety of other paints if applied over them, making a nasty mess in the process, so I generally either use them on their own or as primers.

Modeller's oil-based enamels can be applied over Halfords paints with no problems, but not the other way around.

If in any doubt, first do a thorough test on a piece of scrap. The reason I know all about avoiding these disasters is of course that I've made most of the commoner mistakes in my time, and spent long hours with brake fluid, wet-and-dry and bad language as a result.

Hope that's helpful,

John