Matching Plastic and Metal Cases?

Heatvent

New Member
Sep 19, 2019
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Hi, I have an old 386 in need of refurbishing. The front of the case and bezels on floppies are all plastic. So I am ready to go there. The case itself however has also gotten dirty / dull and I know it's not plastic yellowing it does look a little yellowish to me and won't match the retrobrite'd plastic pieces.

Any suggestions here? There are actually two issues for me (1) the color won't match the retrobrite plastic, and (2) there are some small dings that lead to minor rusting. So I can either try to restore the color as best I can and touch up the rust areas or just paint the whole thing. Definitely leaning towards the latter with the only major concerns of finding correct color and matching the original finish which was kind of rough / not smooth with noticeable raised bumps. Not sure if I could recreate this finish. Some initial thoughts are...
  • I have tried looking for matching spray paints but it's difficult to find an exact match and I assume it will still look "off" compared to the original plastic pieces no matter how hard I look.
  • I could take the retrobrite'd plastic pieces to a home paint store and get a quart of something matched. Not sure what would be good for this purpose. Probably not latex. I would think oil based enamel would possibly be a good choice but this option will probably be a bit pricey ($20 a quart?).
  • I am thinking a matte or satin finish but probably won't be able to recreate the "factory" finish unless I learn how that is done.
Wondering what others might have done. Are there other "custom color" options out there. Just get something close and live with it? Any tips on getting that factory finish? Or, just try to clean it up ... it's old not new.

Thoughts, suggestions, comments would all be welcomed.
 

cml37

Moderator
Staff member
May 19, 2019
116
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Washington, D.C. Area
Hi, I have an old 386 in need of refurbishing. The front of the case and bezels on floppies are all plastic. So I am ready to go there. The case itself however has also gotten dirty / dull and I know it's not plastic yellowing it does look a little yellowish to me and won't match the retrobrite'd plastic pieces.

Any suggestions here? There are actually two issues for me (1) the color won't match the retrobrite plastic, and (2) there are some small dings that lead to minor rusting. So I can either try to restore the color as best I can and touch up the rust areas or just paint the whole thing. Definitely leaning towards the latter with the only major concerns of finding correct color and matching the original finish which was kind of rough / not smooth with noticeable raised bumps. Not sure if I could recreate this finish. Some initial thoughts are...
  • I have tried looking for matching spray paints but it's difficult to find an exact match and I assume it will still look "off" compared to the original plastic pieces no matter how hard I look.
  • I could take the retrobrite'd plastic pieces to a home paint store and get a quart of something matched. Not sure what would be good for this purpose. Probably not latex. I would think oil based enamel would possibly be a good choice but this option will probably be a bit pricey ($20 a quart?).
  • I am thinking a matte or satin finish but probably won't be able to recreate the "factory" finish unless I learn how that is done.
Wondering what others might have done. Are there other "custom color" options out there. Just get something close and live with it? Any tips on getting that factory finish? Or, just try to clean it up ... it's old not new.

Thoughts, suggestions, comments would all be welcomed.
Great question. For all of my retro PCs, I pretty much clean them up and take a magic eraser to them for the tough spots and call it a day. Too afraid to retrobrite or otherwise! I figure they've earned their battle scars :)
 

Heatvent

New Member
Sep 19, 2019
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Thanks for your thoughts. I am working on two similar PCs. One had a better life, it's just the front yellowed way more than the metal case and is noticeably heavier on one side. I am on the fence on retro-briting this and won't do much more than the magic eraser on the paint for this PC. I could probably using rubbing compound to get back to the original color but would end up with a smooth rather than textured finish. Anyway, I get your point as part of me is just saying leave it and let it look like it's an antique.

The other PC has had a rougher life. It was in a warehouse in Texas for as near as I can tell most of the last two decades. There are a couple of nicks on the outside of the metal case and rust in the front where the plastic connects. I could see the rust starting underneath the paint where it deteriorated on the outside surface and couldn't help but remove the rust as over time this would have continued to spread. Now I have a few spots that are sanded and, well, will need to paint.

Going down the color match path it doesn't look too promising. Sherwin Williams will color match and have one paint for metals (gallon only) and also do custom spray paints. I haven't gotten a quote for the custom spray but my expectation is it will be $25+ as well. I could always do latex but something just doesn't seem right about that. Final option is to select the closing thing possible from the spray paint aisle and see how close we get. I will likely try this option and as long is the contrast is slight, just live with a minor difference.
 
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cml37

Moderator
Staff member
May 19, 2019
116
33
28
Washington, D.C. Area
Thanks for your thoughts. I am working on two similar PCs. One had a better life, it's just the front yellowed way more than the metal case and is noticeably heavier on one side. I am on the fence on retro-briting this and won't do much more than the magic eraser on the paint for this PC. I could probably using rubbing compound to get back to the original color but would end up with a smooth rather than textured finish.

The other PC has had a rougher life. It was in a warehouse in Texas for as near as I can tell most of the last two decades. There are a couple of nicks on the metal and I could see the rust starting underneath the paint where it deteriorated. I couldn't help but remove the rust as over time this would have continued to eat through. Now I have a few spots that are sanded and will need to paint.

Going down the color match path it doesn't look too promising. Sherwin Williams will color match and have one paint for metals (gallon only) and also do custom spray paints. I haven't gotten a quote for the custom spray but my expectation is it will be $25+ as well. I could always do latex but something just doesn't seem right about that. Final option is to select the closing thing possible from the spray paint aisle and see how close we get. I will likely try this option and as long is the contrast is slight, just live with a minor difference.
Would that warehouse in Texas happen to be Computer Reset? I have a few machines from there :)
 

Markeno

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Jul 19, 2019
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hobbytronics.home.blog
Myth: Old Computers are White.

Are you sure the color of the paint has changed? Odds are lower that paint has changed in any significant way. It can though, the best place to tell would be on any protected area, like a painted bent under lip that was out of the light. There is the point that paint in shadow can darken though too.
 

Heatvent

New Member
Sep 19, 2019
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Would that warehouse in Texas happen to be Computer Reset? I have a few machines from there :)
It's actually a company called Computer Fusion. They seem to have a bought up truckloads of liquidated PC's when companies changed over, went out of business, etc. and have stockpiled them to be sold off for parts. I think they generally sell to businesses that need to keep some old computer running for some purpose and charge a premium. They were nice enough since I was a hobbyist and was looking at a Leading Technology 6800SX 386SX clone that, while fairly popular and carried at the Office Max's, Best Buys and Comp USA's, isn't really a business machine or a collector's item. For me, it was the first PC I owned and could afford and they are a bit hard to come by because most of them probably ended up in the junk yard.

Myth: Old Computers are White.

Are you sure the color of the paint has changed? Odds are lower that paint has changed in any significant way. It can though, the best place to tell would be on any protected area, like a painted bent under lip that was out of the light. There is the point that paint in shadow can darken though too.
For some color examples, here is a keyboard for a 6000SX I found in a forum. You can see the difference where there was something paper taped over the keyboard for a long time.

zgfs5dj3zvc21.jpg

Here is a picture of a nice clean 6800SX that I missed on Ebay...

00H0H_hVNlhVjx1lI_1200x900.jpg

So it's not white, it's more of white with a hint of cream color. The above is not the one I have of course. The issue with the one I am restoring is I took care of the rust spots on the exterior of the case and therefore need to repaint the metal part of the case. So if I am doing this, I might as well try to restore to original color. I would want to retrobrite the plastic a little to get rid of the little bit of noticeable yellowing and would prefer to match the paint vs. trying to pick something close that doesn't look right.
 

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Markeno

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Jul 19, 2019
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It is possible they never exactly matched, by a small margin. If you are focused on matching, I would get the plastics where you want them, then try to find a paint that matches. There are companies you can buy custom colors from, but I haven't done that. How you get a proper match I can't say, pictures on the internet are never the same as what you get exactly. Depending on your monitor, the lighting and all kinks of factors. That is to much for me to care to mess with.

If you find a gloss paint and want a semigloss or flatter finish, you can put a matte clear on it. Or vice versa.

You should test how paints mix. Some Spray Paints will lift others, even clear coat may even if the base paint is fully dry (possibly even the vintage paint). The solvent in the one paint can soften the existing layer and cause it to lift.

You could also just get some model paint and custom mix it to make some touch up paint for the exposed areas where the rust had been. That could improve the look, and help prevent more rust.

A new paint over the case may not be as durable as the original, so that is something I try to keep in mind. I normally would go for preserving what is there than replacing it if I could. That doesn't mean I don't repaint items. Certainly it is your equipment and it is up to you to do what you want it with it. I don't generally try to preserve it due to some "value", I figure by the time I get rid of any of it, it won't likely be worth anything anyways. I don't collect vintage electronics because I am looking to sell them for big bucks someday.
 

Heatvent

New Member
Sep 19, 2019
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It is possible they never exactly matched, by a small margin. If you are focused on matching, I would get the plastics where you want them, then try to find a paint that matches. There are companies you can buy custom colors from, but I haven't done that. How you get a proper match I can't say, pictures on the internet are never the same as what you get exactly. Depending on your monitor, the lighting and all kinks of factors. That is to much for me to care to mess with.

If you find a gloss paint and want a semigloss or flatter finish, you can put a matte clear on it. Or vice versa.

You should test how paints mix. Some Spray Paints will lift others, even clear coat may even if the base paint is fully dry (possibly even the vintage paint). The solvent in the one paint can soften the existing layer and cause it to lift.

You could also just get some model paint and custom mix it to make some touch up paint for the exposed areas where the rust had been. That could improve the look, and help prevent more rust.

A new paint over the case may not be as durable as the original, so that is something I try to keep in mind. I normally would go for preserving what is there than replacing it if I could. That doesn't mean I don't repaint items. Certainly it is your equipment and it is up to you to do what you want it with it. I don't generally try to preserve it due to some "value", I figure by the time I get rid of any of it, it won't likely be worth anything anyways. I don't collect vintage electronics because I am looking to sell them for big bucks someday.
Thanks for the advice. I think you are right that they probably never matched. Where I sanded the rust spots you can see the underlying primer layer and you can see a noticeable difference in the paint color as it feathers out. The closer to the center it looks lighter and more like the plastic. Outside the area sanded it looks dingy and slightly yellow. Whether this is due to UV, ground in dirt over time or some other reaction, not sure but you can see the paint does change color.

On the 6000SX, I ended up retrobriting the front bezel somewhat. It reduced the yellowing although not completely. Even at the level I retrobrited, the plasitic is a shade or so lighter than the metal case (after scrubbing with a magic eraser). I am fine with the slight variation and I am only going this far with this one. The reality is you have a number of different plastics between the bezel, power buttons, bezel on the floppy drives and the metal case. These may have all closely matched from the factory but all have slightly different plastic or finishes. So to get all of this to perfectly match again would be an exercise in futility. Anyway, the "cleaned up" 6000SX is looking pretty good.

For the 6800SX, I might try the touch-up route but I am pretty bad at mixing and matching. That is why I wanted to go with a computer color match. However, oil based paints aren't really available around me and any paint they have for metals is fairly expensive ($25 plus) for this small job. I will probably just find the closest spray paint and use that. This PC is not very collectible and has been through the ringer as far as I can tell. All drives seem to be shot and the motherboard has intermittent problems and fuzzy VGA output (I found a replacement MB on Ebay). So, given the poor starting condition, I am OK going a little further to bring this back to a condition that will hopefully last.
 

Markeno

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Jul 19, 2019
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hobbytronics.home.blog
I certainly understand. I happen the have 2 C64s, one being pretty good original condition, the other was rather rough when I got it. I am exercising a bit more leeway in restoring the rough one.
 

Heatvent

New Member
Sep 19, 2019
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OK, current status is I have removed all rust spots from the case using evaporust and/or sandpaper. I painted the inside of the case light gray and I painted the outside of the metal top part of the case with acrylic latex house paint. I ended up using a latex eggshell sample from Menards that was color matched. Benjamin Moore had a direct to metal alkyd paint, but it was $28 for a quart. This would have been a better option but I couldn't justify the cost. The Menards 8 oz tester was $4.

I first put on 2 coats of Rustoleum spay primer, then 2-3 coats of the acrylic latex paint. Then I sanded smooth and spayed with 2-3 coats of spray clear satin. I did not repaint the outside of the bottom of the case because it was in pretty good shape (no rust) and the back of the case had the original manufacturer stickers that I didn't want to mess with. I am going to clean up a couple of small stubborn spots on the case bottom with a magic eraser. Then I may give the bottom a coat of the satin clear to get sheen to match. The color on the top metal part of the case is pretty close to the bottom of the case so the difference isn't noticeable and will be covered up / not visible. So far pretty pleased with how it is coming along.

I should also mention that I retrobrited the front plastic bezel before matching color. Hope the finish will be durable, only time will tell. When I get everything done I will post some photos.
 
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Heatvent

New Member
Sep 19, 2019
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Here's some before pictures. I should have taken more but this is what I have. You can see a little bit of rust in a couple of them. Again, wish I took more photos. Under the plastic bezel, the front of the metal case was fairly badly rusted on one side. I am still in reassembly (slowly as I find time). WIll post after photos when I get the time. BTW, mine is the one on the top of the stack of PCs. If you need any old PC parts, you should try Computer Fusion. They are price on stuff that they sell to businesses that are trying to keep old hardware going for some reason or other. But for other stuff they are reasonable to work with. They have a pretty large warehouse of old PCs, monitors, etc. Again, this one is in Texas.2nd intermittent leading tech on the left.JPGDSC02388.JPGIMG_0855.JPG
 
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Heatvent

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Sep 19, 2019
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Here are some after pictures. Just a few loose ends to tidy up (affix caution sticker inside the case, add network card / remove compact flash, install 16mb ram, still a little too much sheen, maybe take down with a magic eraser?).

IMG_0963.jpgIMG_0960.jpgIMG_0956.jpgIMG_0947.jpg