Grundig TK24 mystery substance
 

Hi all, it's been a long time since I posted on the forum although I am an avid viewer. Anyway I have been given this tape recorder and am a bit worried about a small sheet of something which is clamped under three of the electrolytics, it reminds me of a piece of asbestos my Dad brought home from work for me to use with my chemistry set when I was about ten (mid 1970's). So before I plough ahead with the horrendous replacement of the Wima caps that it certainly needs I thought I'd ask if anyone knew what it was and if I should take precautions. I think I've attached a photo.

Re: Grundig TK24 mystery substance
 

It's impossible to say what the composition is of a manufactured board product without having it tested. It is likely to be an ACM from its appearance, and the fact that when the machine was made, such products were thought to be the best for the job. If an ACM, the level of risk it poses again cannot be guessed at without testing which kind(s) of asbestos are present. Personally, I note such things in my register and leave them alone. Many museums seal the product if temperature range does not exceed the limits of the sealant, e.g. in static exhibits.

Re: Grundig TK24 mystery substance
 

It looks like a piece of white asbestos, very common in radios and TVs of the period. It is not brown or blue asbestos which are the more hazardous types. This type of asbestos was fitted to millions of ironing boards up until the 1960's and in its cement form is present in roofing, garages and guttering throughout the UK. I would just give it a water spray if you want to work around it to reduce the spread of fibres. It is there for a reason, possibly to protect the capacitors from heat, so is difficult to replace with anything else.
Neil

Re: Grundig TK24 mystery substance
 

Thanks Lucien and Neil, that being the case I'll just carry on with the job, the capacitors touching it are good so I don't need to disturb it.

Re: Grundig TK24 mystery substance
 

It looks like a previous repairer has picked it up and used it as a spacer when replacing the capacitor.

Re: Grundig TK24 mystery substance
 

I think that looks original to me.

I've not noticed it before in these recorders, although I'm sure I've had similar ones opened up in the past.

The thing to do is not to go sucking up dirt from the innards with an ordinary domestic vacuum cleaner, as the filter won't stop the dangerous particles from being distributed into the air throughout your house - do any cleaning and blowing outside away from the house.

The bottom line is don't worry about it too much and don't disturb it, just do what you have to do to the electronics and then put the case back on and leave it alone. As said before, a lot of vintage electronic stuff has asbestos inside it as heat shielding.

As I always say, if this sort of thing really bothers you, then perhaps the 'hobby' is not for you. The bottom line is just be careful and take the necessary precautions as advised when you come across this stuff.

Re: Grundig TK24 mystery substance
 

Well I managed to do what I had to do without disturbing the asbestos sheet and it's working nicely. Good advice about the vacuum cleaner Techman, I wouldn't have thought of that, thanks for all the replies.

Re: Grundig TK24 mystery substance
 

Also present in Morphy-richards irons. Having replaced dozens of those asbestos pieces in the past and brushed out the remains, I am not in bad shape for 76...

Re: Grundig TK24 mystery substance
 

At minimal cost I got a strip of 2" x 1" sticky 'a' warning labels as a nod towards future dismantlers. If there is a smooth cool surface inside suspect equipment they should stay stuck for a reasonable time. Where aesthetics are not a consideration i have stuck them on the outside (my fuse box and battery charger)

Lab testing is not economic as regards hobbyists so if in doubt- we should assume that the material under scrutiny DOES contain fibre.

Dave