Cleaning gold aluminium Marshall Faceplate

[christarak]

I am hoping this is an easy one. I have just finished a 40 year old Marshall repair, which has 40 years of gunk and solidified body oils on the anodised aluminium faceplate. I would appreciate some tips on how to clean the gunk without removing the letters. I have gently tried methylated spirits (not sure what this is called in the USA...its the stuff you use to dissolve shellac flakes) and WD40 on the back, and I suspect it would remove the lettering.

[Mick Bailey]

Your suspicion about using meths or WD40 on the front of the panel is most likely correct. Over the years the lettering becomes more susceptible to being removed. Not as bad as the white-on-chrome of Fender panels, but it is vulnerable to solvents of any kind. Even strong detergents can damage the surface. I use a mild, foaming car upholstery cleaner sprayed into a dish and applied gently with a cotton swab, avoiding rubbing the lettering too much. There used to be an excellent keyboard/computer cleaner called AF Foamclene that I used a lot, but haven't seen this in a while other than online. You still have to be careful, as even this can lift lettering. The problem is that the screen-printing ink used is oil based and grease from fingers, smoke, etc. binds and reacts over the years to the ink. This changes its nature and makes it more susceptible to being broken down than a recently printed panel would be. Plus you have decades of general ageing at work.

It may seem odd, but human saliva is an excellent and safe cleaner for greasy/dirty residues. Picture restorers apply spit to a cotton swab (cotton buds as we call them, Q-tip or whatever they're called elsewhere) and work on a small square at a time. The enzymes in saliva break down oils effectively and safely. They then wipe over with distilled water. I've also used this method over lettering and used cleaner in the general areas and it's slow but works well.

[dai h.]

>human saliva

good for blood stains also (a small one and not something from an axe muderer)

[Chuck H]

>human saliva

good for blood stains also (a small one and not something from an axe muderer)

Well I guess I'll need to try plan B then

[DrGonz78]

I can’t even tell you how many times I was trying to install software from a CD and it would reach 98-99% complete but never finish. That was when in a desperate ploy I would wipe spit all over the CD to clean it off. I can’t remember really anytime it didn’t work either. Just don’t spit in the wind thinking this will clean my face.

[Chuck H]

Mick offered some great and experienced advice as to what happens to the paints and inks with use and age. Unfortunately there's nothing to be done to reverse this softening of the enamel. My only other suggestion would be that if it's a model for which repro plates are made you could just get a new one. Obviously you'd want to save the old one as well though and I've never tried to remove one so I don't know about the likelihood of bending and damage.

[christarak]

It may seem odd, but human saliva is an excellent and safe cleaner for greasy/dirty residues..

Thanks, Mick. I'll down a couple of litres of water and give it a go. My only concern is that at my age, 2L water will convert to urine faster than saliva. Hmmm.... I haven't tried pissing on the Marshall, although I have often thought of pissing on Mesa amps.
I'll let you know how I get on.

[christarak]

My only other suggestion would be that if it's a model for which repro plates are made you could just get a new one.

The customer said that's a "no go". Oh well. No harm in asking.

[Chuck H]

Ok, no new face plate. For financial or sentimental reasons I wonder, but it doesn't matter. Anyway...

Contrary to Mick's conservative methodology, which is the absolutely safe way to go, you could still experiment with products that might remove the grime without removing the print. After all, the grime WILL be softer and more soluble than the printing to some degree. But this requires bold moves that may damage the printing. I'm thinking something like mild dish soap and water and a soft brush. Like a paint brush. Let the soap and water work for a for a minute too. You're not trying to abrasively remove the grime but rather dissolve it in a way that doesn't damage the printing. After keeping the surface wet for a minute or so softly work the surface with the brush. Immediately remove any soap residue with clear water. Try this in an area with no printing first. If it works then try it in an area with printing. If the back of the amp has equal griminess then surely try it there first. If only the front is dangerously grimy then be judicious about where you try it on printing. Do the grimiest spot and only over a tiny area of print. It's possible that the print will be just strong enough to stay put with this kind of cleaning. If not then you'll have to work AROUND all the printing as Mick described. I lack Mick's patience so I typically try to find a method and cleaner that will work at some risk. I'm USUALLY successful. But I've had to stop efforts short too at times after I've already done a little damage.

[christarak]

Ok, no new face plate. For financial or sentimental reasons I wonder, but it doesn't matter. Anyway...

Contrary to Mick's conservative methodology, which is the absolutely safe way to go, you could still experiment with products that might remove the grime without removing the print.

The customer cited originality, but as I am on a tight budget with this amp, I suspect cost is another factor.
In the end, my solution was using saliva near/on lettering with a cotton bud. In the larger areas of unlettered aluminium I used automotive interior Surface Wipes. It was surprisingly good...and gentle. I tried it gently over the rear lettering without damage. But Mick was right when he said "The problem is that the screen-printing ink used is oil based and grease from fingers, smoke, etc. binds and reacts over the years to the ink. This changes its nature and makes it more susceptible to being broken down than a recently printed panel would be."
I tried the wipes on the grimey front and it started to remove my printed line sample.
THANK YOU CHUCK AND MICK!

[Chuck H]

I've cleaned other (not Marshall) metal plates that were grimy with the soap and water as I described. Once the plates were thoroughly dry I applied a couple of thin coats of rattle can satin urethane. That really helped stabilize the printing, BUT... On the second one I did (not an amp but a CB radio) the urethane did start to melt and blister a printed trim stripe surround on that plate in a couple of places (though all letters and numbers survived). I may have put the first coat on too heavy or maybe in my boldness my luck just ran out. Fortunately it wasn't anything collectible.

[DrGonz78]

The one time that sticks out in my memory was a 1959 Tremolux. The face plate just looked dirtier than I have ever seen. I just took an old microfiber cloth to it just dry at first. I am pretty sure I got the cloth a bit damp with water but no cleaners. Luckily I cleaned it really well and there was barely any pitting in the finish. I think the dirt actually protected the face plate for all those years.

[DrGonz78]

I guess my memory was close but it was a 1958 Vibrolux instead. Here is a picture of all the dirt just rubbed off with a microfiber cloth. I didn't take a before after pic so can't compare. I was shocked it was so clean underneath.

[The Dude]

>human saliva

good for blood stains also (a small one and not something from an axe muderer)

You could have saved me a lot of spitting if you'd posted this last week.

[dai h.]

ha! lol...