Paint bloom after clean up?

2709 Views 9 Replies 4 Participants Last post by pedromorgan, Nov 18, 2007

jukebox

Discussion Starter · Nov 17, 2007

I was hoping someone may have come across this before, and know the best way forward.

I am building a DC kits model of 89001, and at the same time, repainting a Hornby CL82 DVT to match. The 89 was primed with Mr Resin, and then I airbrushed both with an undercoat of Humbrol light gray, so they would match. I then airbrushed Phoenix Precision GNER red, masked the red line off, and followed with GNER dark blue, built up over three or four coats.

For the lining, I used GNER red in a bow pen on clear transfer sheet, because I dont trust myself with a bow pen on the curves around the cab area of either model.

Transfers were from DC kits, with the warning flashes from Modelmaster. I used Microscale Microsol and Microset to help the decals bed down (and it was at this point, I relaised the "GNER" logo is a different size on 89001 compared to the DVT's... but that's life!)

Once that was done, I needed to clean up the models before I top coated with varish, and that's where my problem started.

89001 photo

I immersed the 82 in tepid warm soapy water to removed the marks the puddled decal soloutions had left on the dark blue paint, and as the it air dried, the surface took on a white bloom. I rinsed it again with water, thinking it was something to do with the soap, but it has remained.

89002 photo (2)

Knowing I had to clean it up somehow anyway, I took a chance on the 89, and went ahead and did exactly the same thing to it - but it came away unscathed.

89001 photo (3)

Thinking it might be the Microscale product, and needing a stronger cleaning agent, I carefully tried neat isopropyl alcohol. If I apply this to the surface, the bloom disappears - but as the alcohol evporates, the bloom returns.

Has anyone experienced this before, and if so, is there a way to salvage the DVT?

Cheers

SJ

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pedromorgan

· #2 · Nov 17, 2007

How old was the humbrol paint? some of the last batches were a bit iffy.

I did it another way. i sprayed the whole thing blue and then used the fox transfers for the red stripe and GNER stuff.

I can understand why the alcohol dosent help but i dont understand why it happened in the first place. i dont htink it can be salvaged.

If you live near london i have some of the transfers for the wide red stripe that i can spare.

Peter

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Richard Johnson

· #3 · Nov 17, 2007

QUOTE (jukebox @ 17 Nov 2007, 13:24) <{POST_SNAPBACK}>I was hoping someone may have come across this before, and know the best way forward.

<snip>

Thinking it might be the Microscale product, and needing a stronger cleaning agent, I carefully tried neat isopropyl alcohol. If I apply this to the surface, the bloom disappears - but as the alcohol evporates, the bloom returns.

Has anyone experienced this before, and if so, is there a way to salvage the DVT?

Cheers

SJ

Hi SJ

The alcohol is a water soluble solvent. the microset/microsol are water soluble solvents. The paint surface was probably slightly affected and immersing it in water and detergent has probably let a little "chemical dance" happen.

When U wipe with solvent you are cleaning off the bloom but not stopping the process which is deep within the paint layer.

I'd suggest two possibilities to fix it:

(1) placing them in the airing cupboard for a week and then cleaning - this will give time for the water based solvents to totally leave the paint.

I suspect that it will NOT come back once the reaction has stopped.

(2) After leaving a week clean with a little gentle wiping with as little chemical help as possible, and try to NOT use alcohol or water based (maybe something only slightly moistened with white spirit) hit with a hairdryer to evaporate the last of any cleaner used and add a clear coat which MAY prevent its return or indeed dissolve it so it is invisible.

It may or may not work, but its better than having to strip and re-do if you don't need to!

Richard

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jukebox

Discussion Starter · #4 · Nov 17, 2007

QUOTE (pedromorgan @ 17 Nov 2007, 14:59) <{POST_SNAPBACK}>How old was the humbrol paint? some of the last batches were a bit iffy.

I did it another way. i sprayed the whole thing blue and then used the fox transfers for the red stripe and GNER stuff.

I can understand why the alcohol dosent help but i dont understand why it happened in the first place. i dont htink it can be salvaged.

If you live near london i have some of the transfers for the wide red stripe that i can spare.

Peter

The humbrol tinlet was "fresh" - in as far as it might be fresh in a hobby store in Perth, Western Australia! But no, I think the undercoat is innocent, as the 89 is not affected.

Thanks for the offer on the red stripe - but as you can see, I'm a touch far away. If I can't salvage, I will strip and start again - and use the Fox GNER logos instead of the DC ones. And have the most expensive "observation car" in my collection!

Scott

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jukebox

Discussion Starter · #5 · Nov 17, 2007

QUOTE (jukebox @ 17 Nov 2007, 19:05) <{POST_SNAPBACK}>The humbrol tinlet was "fresh" - in as far as it might be fresh in a hobby store in Perth, Western Australia! But no, I think the undercoat is innocent, as the 89 is not affected.

Thanks for the offer on the red stripe - but as you can see, I'm a touch far away. If I can't salvage, I will strip and start again - and use the Fox GNER logos instead of the DC ones. And have the most expensive "observation car" in my collection!

Scott

Thanks for the encouragement.

I just got brave, and tried brushing a small amount of "Pledge" (our equivalent of the aero modeller's magic potion "Future"), to the end corridor connection. Sure enough, the bloom disappears - although I'll be more confident when it has sat for 24 hours.

Its good to know this can be solved - but even more, I'd like to know what happened, so I can avoid it in future...

Scott

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Richard Johnson

· #6 · Nov 17, 2007

QUOTE (jukebox @ 17 Nov 2007, 19:28) <{POST_SNAPBACK}>Thanks for the encouragement.

I just got brave, and tried brushing a small amount of "Pledge" (our equivalent of the aero modeller's magic potion "Future"), to the end corridor connection. Sure enough, the bloom disappears - although I'll be more confident when it has sat for 24 hours.

Its good to know this can be solved - but even more, I'd like to know what happened, so I can avoid it in future...

Scott

Hello Scott - I'm not surprised its going to work... the bloom is actually a very, very fine surface deposit and as long as the residual water is evaporated out of the paint it'll not come back. I've had the same thing happen and it is "solvable" as a problem.

I'm actually far from you, at DCCconcepts 3/13 Lionel street Naval Base. I build, paint, line and whatever to all my own loco's so if I can ever be of help just ask.

It happened because the chemicals in the micro-sol etc made the paint porous to water, and immersing it let the water, well wetted by the detergent, get into the pain itself - the bloom is a reaction to that.

Next time don't immerse it in water - let the decals dry properly in place then just use a cotton bud moistened with about 20% meths and 80% water OR water with just a tiny amount of detergent in it to remove the glue residue from around the decals (thats what it is - the micro-sol dilutes it and as the solvent is a good "wetting agent" it flows around a bit - the micro-sol itself actually leaves NO deposit at all)

Regards

Richard Johnson
DCCconcepts

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Richard Johnson

· #7 · Nov 17, 2007

QUOTE (Richard Johnson @ 17 Nov 2007, 20:42) <{POST_SNAPBACK}>I'm actually far from you, at DCCconcepts 3/13 Lionel street Naval Base.
Regards

Richard Johnson
DCCconcepts

***Doop - meant to say "not far from you" - sorry

Richard
DCCconcepts

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34C

· #8 · Nov 17, 2007

One cautionary note, keep the treated body in a warm low humidity location for a couple of days before applying the varnish, to ensure that as much water as possible has been removed. Then test a small inconspicuous patch with the varnish. Reason for this is that a little water in the surface of a paint layer giving a bloom can usually be removed, but much less water is required to produce the same effect in varnish: and in this situation it is trapped under the varnish, a much greater problem.

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jukebox

Discussion Starter · #9 · Nov 18, 2007

QUOTE (Richard Johnson @ 17 Nov 2007, 20:42) <{POST_SNAPBACK}>....'m not surprised its going to work... the bloom is actually a very, very fine surface deposit and as long as the residual water is evaporated out of the paint it'll not come back. I've had the same thing happen and it is "solvable" as a problem.

I'm actually far from you, at DCCconcepts 3/13 Lionel street Naval Base. I build, paint, line and whatever to all my own loco's so if I can ever be of help just ask....

Richard

Here's a shot of the end - hard to believe a gloss varish is all that is needed to make the chalky appearance disappear.

DVT end, after applying Finish

And for those of you watching from the side-lines, appreciate this irony: Here I am, posting a modelling question regarding GNER liveries to a forum in the UK, 10,000 miles away from where am, only to have it answered by someone who not only lives less than 15 minutes from me (I am in Mandurah, Richard!), but who shares my surname.

The truth is indeed stranger than fiction.

Regards

Scott

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pedromorgan

· #10 · Nov 18, 2007 (Edited by Moderator)

Congratulations on your sucess.

i look forward to a picture of the completed pair.

I think its this forums biggest asset that we have people from all over the world all with a common interest able to come together and discuss their hobby. we are soo blaze about it but it really is a fantastic thing to be able to do.

Peter

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