Smoke damage

[govjohn]

Hi. I've just experienced one of the worst things that can happen to us in relation to our hobby/interest and that is a fire in my workshop. Fortunately it is detatched and no one was injured but the damaged caused by the heat and water (from the fire brigade) is extensive even inside closed drawers.

The reason for this post, apart from sympathy, is to ask if any one has experience in cleaning up from this? In particular removing smoke damage from the front panels of test equipment.I realise the insides will need cleaning and I have ordered an ultrasonic cleaner to help with this in conjunction with a suitable juice. If anyone has any ideas that will help in this situation please let me know. In the mean time switch off the supply to the workshop when you finish at night!

John.

[Nickthedentist]

Sorry to hear about this, John, you certainly have my sympathy. Do you know what caused it exactly?

And thank you for the reminder to switch off. Maybe a timeswitch (and smoke alarms) would be a good idea for all of us.

The only thing that comes to mind is the good old dishwasher, with the caveats that aluminium etc. can easily be damaged.

Nick.

[mark2collection]

Sorry to hear the news John, our thoughts are with you.

From experience, if it's light smoke damage to the front of say, an oscilloscope, car polish (not wax) applied sparingly has worked in the past, Autoglym resin polish for example. Heavy smoke damage could be tricky.

Solvents, T-Cut et al tend to remove the legends as well as the paint finish.

My wife laughs at me for having OCD moments regarding switching everything off. Now that she has seen what happens when something electrical 'lets go' it's not nearly so funny.

The workshop has an RCD trip by the door, so when exiting my 'escape room' I hit the trip button. For belt & braces, during thunder storms or holidays/extended periods of absence, I switch the workshop & parts of the house off at the main board. Even our classic cars when stashed away have their batteries removed.

Not nice. For me it was the neighbours fault at our old house, where they were not insured. Two cars, fence, shed, part of the house. Excellent.

Mark

[HamishBoxer]

I am sorry to hear about this, not the first time in our group.

I have smoke soot damaged Ekcos here and I cleaned them up with Foam Cleanser from CPC and a good polish afterwards with BakoBrite or Paste Polishing No 5 from Chas Miller.

[joebog1]

Soft ordinary dish wash detergent, CAREFULLY applied will work some wonders.
Applied with a "squirt/spray bottle " in a ratio of perhaps 3:1 ( water:dish wash liquid) and a few minutes to work, will also yield very fine results.
Do NOT be tempted to "clean immediately", but rather take a little time to really look at the damage.
For meters/dial fronts or potentiometer scale damage be VERY careful, as lots are very old and dry silk screened patterns and cant be replaced. Damaged french polish will not be recoverable, alas!!. Make sure any transformers are GENTLY baked dry, using no more than 70 degrees C.

My sympathy and I wish you well in your endeavors.

Joe

[David Simpson]

John, I'll echo the thoughts of sympathy from the other guys. If you're able to identify the source of the fire, it might help some folk whose power supplies/cabling need extra preventative measures.
Re cleaning, Joe's advice regarding gentle detergent usage is spot-on. Lettering, labelling, etching etc., can be susceptible to strong chemicals. Don't use cellulose thinners, and some old surfaces don't even like turps or meths. Bakelite doesn't mind meths, and cleans up a dream afterwards with FARECLA Paste compound. G6 to start with, then G10 finishing compound to finish with. Some vintage plastics don't like any sort of cleaning chemical. But an overnight soaking in diluted w/u liquid, a good rinse, a gentle dry, then a polish with(don't laugh) - Mr Sheen Multi Surface, can do wonders.

Regards, David

PS. Valves & Dial Glass - very susceptible to losing lettering/numbering with even just wiping with water.

[Diabolical Artificer]

Sorry to hear of your trouble John. Like with any cleaning job on test gear a good blow out with air might be a good idea then a quick clean to get worst off and as it's very hot at present pop stuff outside to dry off a bit with the lids off.

Good luck, Andy.

[Bazz4CQJ]

Hi John, sorry to hear of your event. One of the more harmful things that could have been in your fire might have been PVC. That produces hydrogen chloride when it burns which reacts with atmospheric moisture to form hydrochloric acid which will obviously attack many materials. If you can identify or suspect burnt PVC, that could be worthy of giving that priority when cleaning up.

Re the ultrasonic cleaner, be aware that many of the fluids that are sold to go with them are alkaline and will attack aluminium and some other metals. I've even had corrosion problems with one 'neutral' cleaner used in a bath. Perhaps a mixture of distilled water with 10% IPA could be tried, but keep the temperature at no more than 30'C so the alcohol does not evaporate too quickly.

B

[evingar]

Originally Posted by Bazz4CQJ

. One of the more harmful things that could have been in your fire might have been PVC. That produces hydrogen chloride when it burns which reacts with atmospheric moisture to form hydrochloric acid which will obviously attack many materials. If you can identify or suspect burnt PVC, that could be worthy of giving that priority when cleaning up.


B

I'd echo this.

In certain circumstances it can be more destructive than the actual fire. At "The day job" all structural and cabinet wiring is mandated to to be non PVC. Corrosive damage can spread well beyond the seat of the fire, rendering wiring and equipment racks BER. If PVC was involved in your fire, you would be well advised to inspect the internals of all equipment that has been subjected to the smoke even if externally it looks OK.

I had a house fire (arson! perpetrator was mentally upset, I bear no grudge) many years ago, the overwhelming memory is it was so dark with the black walls, very demoralising. Given that experience my thoughts are (and what I did) is to decorate (the workshop) first, cleaning the "bits" before putting them back, it may seem the wrong way round but a new room lightens the heart.

[linescan87]

I am reminded of the fire that caused alot of smoke damage to John's T.V. shop back in the winter of '99. There was a large lean to shed at the back of the shop which was full of treasure. One night a tramp broke into the shed and felt a bit cold so lit a small fire, which quickly turned into a big fire. Luckily the tramp got out (and evaded capture!)

While the fire didn't spread into the main shop the smoke and water damage was extensive, it took many months to recover.

Like Merlinmaxwell, the first thing he did was to redecorate the shop, then cleared a room upstairs where parts and stock could be sorted and cleaned. It was a hard slog but he got there in the end. RS branded foam cleaner was great for smoke stains.

Best wishes and I hope you get back in action soon.

John Joe.

[WME_bill]

Smoke Damage.
We had a bad fire in the factory where I was working years ago. In the clean area for semiconductors with lots of PVC and Perspex on floors, walls and benches. Lots of hydrochloric acid produced.
All the electronic equipment was dumped or staff allowed to take it away.
I got a nice pulse generator, an audio generator and other test gear.
They seemed fine after cleaning the case and controls and the switches inside and worked well.
But the acid fumes had got inside the case, condensed on the cases of the TO18 transistors and corroded the leads immediately underneath.
A month later, the transistors fell off the circuit boards.
So I had a major repair job, replacing virtually every transistor.
I should have washed the whole unit and circuit board and switches immediately in lots of water.
wme_bill.

[The Philpott]

This is an appropriate slot to mention that one of my safety devices, the ubiquitous Smiths TS820 rotary timeswitch, has just failed in the ON position. I had blobbed it with a black marker previously as it was getting a little noisy (both acoustically and electrically) and the rotary manual adjustment mechanism had come to be less smooth than it should be, so in reality it should have been withdrawn from service a while ago.

This had potential to be a nasty one, as the OFF pegs are firmly in position and the ON/OFF manual override toggle in the corner is in the OFF position, but mains voltage is present on what should be the dead side of the appliance.

Contacts welded closed, perhaps.

Dave

[The Philpott]

TS820 opened up. Contacts welded closed, and the spring which opens and closes them is similar gauge to those that used to be found in ballpoint pens. It asks the contacts to open but cannot order them if they have fused. It was naive of me to expect anything better, and a reminder that these things are basic and have a finite life.

My commiserations to John re. his fire.

[G0HZU_JMR]

Sorry to hear about the fire, that must be quite devastating. Fire is always a huge worry for me so I try and do a few things to minimise the risks. But some risk will always be there.

I turn off both my benches every night (and during the day if not in use) and I also try and arrange my test gear/appliances such that there is very little in the way of flammable stuff on the shelves above each electrical item. By (easily) flammable I mean books, magazines, cardboard containers, plastic boxes and random paper notes.

Every so often I try and re-enforce this rule by trying to remove anything unnecessary on the shelves as it does tend to build up over time. I also bought a decent size CO2 fire extinguisher and large fire blanket which I hope I will never need.

I've seen some workrooms on eevblog where the test gear is on the lower shelves and there are several shelves of cardboard boxes and paper files and books directly above this. Some even have files/books/boxes crammed directly on top of things like (old) scopes and power supplies. That is the recipe for a rapid firestorm even from a tiny and brief flame from a faulty scope or mains inlet.

I do recommend people take a quick look around to see what flammable items can be relocated to minimise the speed a fire might take hold.