Master spray job

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roganjosh
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Master spray job

Post by roganjosh » Wed May 30, 2018 8:25 am

I picked up a couple of empty Master 128 cases last year. Both are very yellowed. One of them has obviously had something with a straight edge put on top such that half the case is yellow and the other cream. I suspect that such a two-tone case will not respond well to RetroBrite treatment, even multiple ones, and so am considering painting it. Given its condition and its 'spares' status it would be a harsh person who considered that a very sacrilegious act.

Search terms in this forum have produced limited suggestions for doing so; I'm therefore looking for advice from any others who've managed to achieve the look of an original Master using (e.g.) an ABS-safe spray paint. Particularly,

a) Colour: I see that someone has successfully used RAL1013 (Oyster White) for an Arc. What would be the best make/colour for a Master? The same?

b) Primer: Are there any recommendations for a primer?

c) Finish: I see that there are Matt, Satin & Glossy variants of 'ralcolour' sprays. Which would give the most natural finish (including what type of varnish [e.g. clear acrylic] if Matt is used)?


Alan

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Re: Master spray job

Post by lcww1 » Wed May 30, 2018 10:25 am

You could always try retrobrite first - if it doesn’t turn out well, then you can still paint the case!

I’ve retrobrited a Master case with acceptable results, but see this thread (and others on *.) for more info: viewtopic.php?f=41&t=13438

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sirmorris
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Re: Master spray job

Post by sirmorris » Wed May 30, 2018 10:42 am

I use vinyl dye to colour plastics. It apparently bonds with the plastic rather than covering it, so it doesn't chip or peel. It also doesn't affect the texture of the surface you're painting as much as a regular paint. The colour range is slightly limited though, and it's more expensive. Still worth considering imho.

https://www.vinyldye.co.uk/All-Vinyl-Dye-Color-Sprays

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Re: Master spray job

Post by roganjosh » Wed May 30, 2018 5:37 pm

Thanks both.
I RetroBrited both my Masters last summer and they turned out pretty well. However, they've subsequently re-oxidised, even though they've been kept away from direct sunlight. It seems they do, as some say, need a protective varnish; in effect a paint job. That's why I'm interested in exploring the direct paint route as an alternative since both methods would both seem to compromise the initial state of the case, but the paint might end up giving a better finish.


The vinyl dye approach sounds good sirmorris and, as you say, would do a good job in preserving the texture. Given that colours shown in browsers are often not representative of the actual colour, may I ask which one you think gives the most Master-like effect? I'm assuming it would be their 'Bone' shade. I'd also appreciate knowing whether you subsequently treated them with their Matte or Glossy 'add-ons' (as they seeem to call them) to get a more original-looking effect.

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Re: Master spray job

Post by sirmorris » Wed May 30, 2018 5:44 pm

I've never used bone, and I'm always happy with the finish as-is so I can't be any help there I'm afraid. Sorry :(

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Re: Master spray job

Post by steve3000 » Wed May 30, 2018 6:04 pm

roganjosh wrote:
Wed May 30, 2018 8:25 am
I picked up a couple of empty Master 128 cases last year. Both are very yellowed. One of them has obviously had something with a straight edge put on top such that half the case is yellow and the other cream. I suspect that such a two-tone case will not respond well to RetroBrite treatment, even multiple ones, and so am considering painting it.
I've retrobrighted a few like this. Particularly bad are sticky labels that have been placed on the top or side of a computer or disc drive back in the 80's and protected a credit-card sized rectangle from yellowing over time - it looks awful after the label is removed...!

I just apply the retrobight mix to everything apart from the non-yellowed area and after a couple of goes the result can be surprisingly good. I'm sure I have some photos of a particularly bad disc drive I did earlier this year, will post them up if I can find...

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Re: Master spray job

Post by steve3000 » Wed May 30, 2018 6:42 pm

tn_DSCF3753.JPG
Disc Drive
tn_DSCF3755.JPG
Label gap up close
tn_DSCF3757.JPG
Process
tn_DSCF3763.JPG
Result

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Re: Master spray job

Post by pcbbc » Thu May 31, 2018 12:41 pm

Does the use of the blonde dye also increase the double the "density" of the drive to 80T? :oops:

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Re: Master spray job

Post by roganjosh » Thu May 31, 2018 1:31 pm

Impressive peroxy acid job. Do you varnish things afterwards (if so what make/type). I may get the marigolds out again, however I don't wish to hijack my own thread so am still dyeing (apologies) to hear peoples' experiences with original-look paint.


Alan

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Re: Master spray job

Post by z0m8ied0g » Thu May 31, 2018 4:56 pm

sirmorris wrote:
Wed May 30, 2018 10:42 am
I use vinyl dye to colour plastics.
I've got a set of these that i'm intending to use on my BBC master, its going to be black with a white owl logo across the top.
I'll let everyone know how it turns out.
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Re: Master spray job

Post by mattdy4 » Mon Jul 30, 2018 9:45 am

Sorry I know this thread is a couple of months old now but did you or anyone else try vinyl dye?

I have a Micro ready for retrobriting but I'm leaning towards dyeing it instead as it's more permanent / even but unsure of the colour needed (white, bone etc)

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Re: Master spray job

Post by roganjosh » Wed Aug 01, 2018 10:58 pm

mattdy4 wrote:
Mon Jul 30, 2018 9:45 am
Sorry I know this thread is a couple of months old now but did you or anyone else try vinyl dye?

I have a Micro ready for retrobriting but I'm leaning towards dyeing it instead as it's more permanent / even but unsure of the colour needed (white, bone etc)
I decided to give it a while to see whether anyone else would chip in, and then a series of retro projects got in the way. Thanks for reminding me. I've got some Brillo Bone dye on order so I'll be giving it a whirl in the near future. I'll report back with at least a description of the result, perhaps more if I can ever get my cameras to produce something better than a blurred image.

Alan

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Re: Master spray job

Post by colonel32 » Thu Aug 02, 2018 3:31 am

How well does vinyl dye cover?

Can you do black over cream ABS, or bone over black ABS, without it looking patchy?

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Re: Master spray job

Post by roganjosh » Thu Aug 02, 2018 6:30 am

colonel32 wrote:
Thu Aug 02, 2018 3:31 am
How well does vinyl dye cover?

Can you do black over cream ABS, or bone over black ABS, without it looking patchy?
Their blurb says that a 150ml aerosol can will do 1 to 1.5 square metres with 3 fine coats and that it usually takes 3 or 4 fine coats to do the job. Their site shows how someone dyed a black freeview box to white with no apparent difficulty. They do warn that a lot of black plastics can have a top layer providing a sheen, and that that needs to be removed with wet and dry before dyeing.

Alan

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Re: Master spray job

Post by roganjosh » Tue Aug 07, 2018 1:53 pm

Here are the results I achieved using the Brillo Bone colour vinyl dye from vinyldye.co.uk. This isn't a recommendation one way or the other, it's entirely your responsibility whether you do the same. I also apologise for the photo quality - what my cameras lack in picture quality is more than matched by my uselessness as a photographer.

The first picture is how the top of my case looked before the treatment:
pre-vinyl.JPG
You can see that it's yellowed considerably apart from the left two thirds of the top surface where something must have rested on it shielding it from the sun. I prepared the case using Flash liquid to remove any grease followed by a thorough wash and then a rub-down with IPA. If you order anything from the vinyldye company they'll suggest that you buy their own such treatments instead. I used masking tape to protect the black areas.

After 5 light coats of the dye the case looks like this:
post-vinyl.JPG
The colour is creamier (darker) than a virgin Master and there is a faint ashen pinkiness to the colour hence, I suspect, the name of 'bone'. I find the finish pleasant enough. For the purposes of comparison the photo shows the untreated inside bottom of the case. That area was retrobrited a year ago and is already noticeably yellow. Tastes will vary but I find the outside finish much more satisfactory than the inside. Given that this is a dye rather than a paint you should not expect it to fill in any scratches. I would describe the finish as satin rather than glossy or matt. I think that's the closest to the original finish and I don't intend using the company's glossy or matt preparations. After drying for a day the smooth areas of the case feel very slightly rough.

The spraying went without incident. On their recommendation I shook the can (with internal ball bearing) vigorously for 10 minutes before starting. I left 15 minutes between each coat in an outside temperature of 24C. Their web site, as previously mentioned in this topic, says that 3 or 4 light coats are sufficient. A follow-up email from the company after the purchase suggested 4 or 5 instead. A 150ml can is enough to do 5 coats on both the external surfaces of the case top and the visible areas of the case bottom (i.e. not its underside), with a small amount left over. The spray contents are marked as an irritant and it reeks of toluene so you should at least spray outside and in the direction of any breeze. I advise that you wear a mask.

I had nothing to lose in applying this treatment as it was a spare case in poor cosmetic condition. It now looks rather good. I've even ordered a couple more cans to do my other Master cases if/when the mood takes me. For now I'll shift the innards of one Master into the dyed case and see how it looks after a year before doing so. Given the nature of the dye-plastic bond it ought to look the same.


Alan

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Re: Master spray job

Post by colonel32 » Tue Aug 07, 2018 10:37 pm

Thanks for the comprehensive write-up, Alan. I think it looks great!

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Re: Master spray job

Post by Elminster » Tue Aug 07, 2018 10:56 pm

who Will be the first rebel and do a blue case!?

Looks good though, I never retrobrite, but dying looks a possibility if my cases ever get too bad.

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Re: Master spray job

Post by mattdy4 » Wed Aug 08, 2018 5:05 pm

Fantastic write up, thanks. Looks great too, I promise I'll try it myself soon and post B&A pictures

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Re: Master spray job

Post by roganjosh » Sat Aug 10, 2019 8:53 pm

A year on from doing the spray job I can report that the colour of the case hasn't changed. Vinyl dye, as surmised, appears to provide a long lasting solution for hobbyists with a dislike of yellowed cases. I unashamedly include myself in that category.

I had a quick look at their "Natural" preparation recently. That's one's far too dark, assuming that you're after a reasonable approximation to the original colour. I've therefore stuck with "Bone". You can see my comment about that colour earlier in the thread.

Alan
Last edited by roganjosh on Wed Mar 25, 2020 7:24 am, edited 1 time in total.

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Re: Master spray job

Post by jms2 » Tue Mar 24, 2020 10:45 pm

Hello Alan,

I have been reading about your vinyl dye experiments with interest. Having just resprayed my Compact case using RAL1015 colour paint, I'd like to get the plastic trim bits to match it reasonably closely. "Bone" definitely looks a bit lighter and pinker, but "Champagne" looks a perfect match. Have you tried that one at all?

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Re: Master spray job

Post by roganjosh » Wed Mar 25, 2020 7:30 am

I haven't tried Champagne. I was quite likely put off because that just happens to be the colour of the bathroom suite! I also made a mistake above when I mentioned that "ivory" looked too dark. That should have been "Natural" is too dark. I've corrected that.

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Re: Master spray job

Post by jms2 » Wed Mar 25, 2020 8:39 am

I did wonder about Natural, so its useful to clear that up.

I might give Champagne a try then, and I'll report back on how it goes. I might also try their glossy overcoat, because the Compact's trim bits are meant to be shiny.

I have tried Retrobriting over the last few sunny days, and whilst it is working, I'm seeing more streaking and blotching than I have had in the past. I think its the clingfilm actually - pretty sure I never used it before.

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Re: Master spray job

Post by daveejhitchins » Wed Mar 25, 2020 11:03 am

If it's of any use (?) I had an Acorn case 'colour-scanned' when I had the AP5 (etc.) cases made. The feedback on the colour was:

BS10B17 Oatmeal - the actual number they gave was BS10B17 SG

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Re: Master spray job

Post by jms2 » Wed Mar 25, 2020 5:30 pm

That's a BS4800 colour reference Dave. There are online convertors which give the equivalent RAL colour reference for a given colour in a different system, but there isn't a straightforward equivalence in this instance. 10B17 is definitely "greyer" than RAL1015 - but that doesn't mean that either are necessarily wrong.

In fact, you matched to an Electron - is that even the same colour as a BBC? I'm not 100% sure that it is.

It would be nice to be able to specify what "BBC beige" is using various different colour systems. For these vinyl dyes it's academic though, because the products are only specified by name, not by RAL reference or anything else as far as I can see.

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Re: Master spray job

Post by daveejhitchins » Thu Mar 26, 2020 8:03 am

Don't 'good' paint shops now have colour matching technology? You could always have something matched and mixed to suit! ??

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Re: Master spray job

Post by jms2 » Thu Mar 26, 2020 8:54 am

You can for paint. But for vinyl dyes, there seem to be two brands and their colour charts are what they are, so you can't colour match except by giving it a go.

What I was getting at was that certain products are available with different colour system specifications and so it would be handy to know how these all relate to one another. There doesn't seem to be an easy online way to do it, which surprises me a little bit. However I can approximate to it, because I have an AP5 in 10b17, the thing I've just sprayed in RAL1015 and a non yellowed Master. I'll get them all together and report back... :D

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Re: Master spray job

Post by jms2 » Thu Mar 26, 2020 11:23 am

That was interesting!

The photo below shows (clockwise from left):
- A Master that has never seen any UV.
- Compact base unit, sprayed in RAL1015
- Insides of Compact trim pieces
- Electron, bit yellowed but I think I Retrobrited it.
- AP5
- Interior of BBC B case, the exterior is a bit yellowed and I'd say that (surprisingly) the inside is too, a bit.
IMG_2906[1].JPG
Conclusions:
1) I think all the plastics were originally the same colour (or at least, were intended to be, within manufacturing tolerances).
2) Dave's 10B17 "Oatmeal" colour is a very good match, almost perfect in fact.
3) RAL1015 is distinctly pinker, almost peach compared to the original. In fact it is closer to a slightly-yellowed BBC than to the "true" colour. By comparison the Oatmeal colour contains more grey/green.
4) They all look pretty much identical in the photo (the differences are more obvious in reality of course). RAL1015 is definitely an acceptable substitute in practice.

The funny thing is, if you showed me RAL1015 and the Oatmeal colour in isolation from an actual machine, I would say the RAL colour is more accurate. It just goes to show how your perception/memory can be flawed. I do wonder whether CUB monitors were actually painted in this RAL colour actually, and that's where the false memory comes from.

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Re: Master spray job

Post by Kazzie » Thu Mar 26, 2020 11:52 am

jms2 wrote:
Thu Mar 26, 2020 11:23 am
I do wonder whether CUB monitors were actually painted in this RAL colour actually, and that's where the false memory comes from.
Might it be influenced by the lighting used where you used Beebs in the days of yore?
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Re: Master spray job

Post by 1024MAK » Thu Mar 26, 2020 12:03 pm

Coloured objects may look different colours depending on the light source.
So here are four different light sources:
  • Natural daylight (the weather conditions and time of day also have an effect)
  • Light from fluorescent lights (keep in mind that there are at least three different phosphor types just for linear tubes alone)
  • Light from tungsten filament lamps (normal light bulbs)(long life lamps have a slightly different colour to 1000 hour lamps)
  • LED lighting (many different colour types)
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Re: Master spray job

Post by sbadger » Thu Mar 26, 2020 12:18 pm

1024MAK wrote:
Thu Mar 26, 2020 12:03 pm
Coloured objects may look different colours depending on the light source.
So here are four different light sources:
  • Natural daylight (the weather conditions and time of day also have an effect)
  • Light from fluorescent lights (keep in mind that there are at least three different phosphor types just for linear tubes alone)
  • Light from tungsten filament lamps (normal light bulbs)(long life lamps have a slightly different colour to 1000 hour lamps)
  • LED lighting (many different colour types)
Mark
A Little OT, but a nice little TED talk on Colour Perception https://www.ted.com/talks/beau_lotto_op ... anguage=en
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