Bad Smell from Old PCB Material ? - UK Vintage Radio Repair and Restoration Discussion Forum

Aub · 1st May 2020, 7:55 am

Hello all,

Yesterday I began making a microphone pre amp to use with my amateur radio transmitter. For the front panel, I decided to use a piece of double sided PCB that I've had for decades. This was easy to cut, using tin snips and easy to drill. However, it makes a really bad smell, almost like burning and I'm wondering if it's dangerous, contains carcinogens
etc. It's not fibreglass but the brown stuff ( paxolin? )

Any advice welcome

Thanks
Aub

sortedradio · 1st May 2020, 8:09 am

It sounds like SRBP (Synthetic Resin Bonded Paper), widely used still today, as it's cheaper than fibreglass. It's always wise to wear a mask to avoid breathing in dust when drlling or cutting, but I've never heard of it being carcergenic.

Aub · 1st May 2020, 10:04 am

Thanks for the reply. Ah yes SRBP, i remember that now. It still smells so bad, after hours not touching it. I think i'll start again with something else.

Cheers

Aub

Lloyd 1985 · 1st May 2020, 10:30 am

PCB material always stinks when you cut or break it, even just snapping an old PCB makes it smell, I’ve never worried about it, it does settle eventually, though it’s a good idea to wear a mask if cutting or filing it, I’ve tried breathing the dust, and it’s not nice!

Regards
Lloyd

Cobaltblue · 1st May 2020, 10:35 am

It's that old familiar smell from my youth cutting and filing SRBP.

And it smells even worse when it burns due to water going down the back of your old GEC TV when your watering the pot plants!

Call me a sadist but I don't mind the smell its kind of comforting that not everything changes

Cheers

Mike T

David G4EBT · 1st May 2020, 10:55 am

The smell from drilling filing or sawing SRBP is phenol formaldehyde resin I believe, also used in the production of Bakelite. If I'm not mistaken, phenol is carbolic acid. There used to be a factory close to the M1 about Junction 28 - Chesterfield area and the phenolic smell was all pervading when driving past. I rather like the smell, but then I like the smell of felt tip markers and meths too, but don't make a habit of inhaling! (On the other hand, I can't abide the smell of bananas or hyacynths, so I guess well all have our sensitivities).

This link is relevant:

https://en.wikipedia.org/wiki/Phenol_formaldehyde_resin

Philips210 · 1st May 2020, 2:36 pm

Hi.

I've noticed this too in recent years. As a youngster, I recall the smell of cutting and filing the dark SRBP and Veroboards but kind of liked it at the time and enjoyed the aroma as being part of the electronics hobby.

Nowadays I find it overbearing and hate using it. I wondered if there was something going on making it outgas more now than when it was new. This kind of goes against the grain as generally the outgassing ought to become less over time.

Then I started taking notice of other smells and odours which I never gave any attention to in the past. Any solvent paints, spirits, petrol, vehicle exhaust fumes, bonfires etc all seem very potent compared to years ago.
I had learnt that the modern petrol does smell more these days if it has been hanging around in a can or lawn mower for a few months. I think it may be because of the ethanol that's added.

My latest bugbear is the new workshop that I've recently built. The OSB floor and roof odours were too overbearing to work in there. After many months it is easing off but I still need to have the windows and door open to feel comfortable working in there.

In my case, although I haven't been diagnosed, I believe I've developed an ultra sensitive sense of smell (hyperosmia).

I try to avoid smelly chemicals now where possible or at least work outdoors, weather permitting.

Regards,
Symon.

Aub · 1st May 2020, 5:20 pm

Thanks for all the replies, very interesting.
I've used and cut fibreglass pcb loads of times, but not srbp. I only used it as I had a largish sheet of it id never used.
Anyway, I've remade the front panel in aluminium.

Cheers

Aub

Philips210 · 1st May 2020, 10:27 pm

I've sometimes wondered if it's in order to paint SRBP in order to seal it from the fumes. If it's OK to paint, then does anyone know what type of paint is safe to use? I suppose an oil based enamel paint would be suitable. I also wonder about using water based acrylics which are much safer generally.

Regards,
Symon

1st May 2020, 7:55 am	#1
Aub Nonode Join Date: Mar 2005 Location: Nuneaton, Warwickshire, UK. Posts: 2,037	Bad Smell from Old PCB Material ? Hello all, Yesterday I began making a microphone pre amp to use with my amateur radio transmitter. For the front panel, I decided to use a piece of double sided PCB that I've had for decades. This was easy to cut, using tin snips and easy to drill. However, it makes a really bad smell, almost like burning and I'm wondering if it's dangerous, contains carcinogens etc. It's not fibreglass but the brown stuff ( paxolin? ) Any advice welcome Thanks Aub __________________ Life's a long song, but the tune ends too soon for us all.

1st May 2020, 8:09 am	#2
sortedradio Heptode Join Date: Jan 2008 Location: Sheffield, South Yorkshire, UK. Posts: 654	Re: Bad Smell from Old PCB Material ? It sounds like SRBP (Synthetic Resin Bonded Paper), widely used still today, as it's cheaper than fibreglass. It's always wise to wear a mask to avoid breathing in dust when drlling or cutting, but I've never heard of it being carcergenic. __________________ Martin BVWS member GQRP Club

1st May 2020, 10:04 am	#3
Aub Nonode Join Date: Mar 2005 Location: Nuneaton, Warwickshire, UK. Posts: 2,037	Re: Bad Smell from Old PCB Material ? Thanks for the reply. Ah yes SRBP, i remember that now. It still smells so bad, after hours not touching it. I think i'll start again with something else. Cheers Aub __________________ Life's a long song, but the tune ends too soon for us all.

1st May 2020, 10:30 am	#4
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,817	Re: Bad Smell from Old PCB Material ? PCB material always stinks when you cut or break it, even just snapping an old PCB makes it smell, I’ve never worried about it, it does settle eventually, though it’s a good idea to wear a mask if cutting or filing it, I’ve tried breathing the dust, and it’s not nice! Regards Lloyd

1st May 2020, 10:35 am	#5
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 6,857	Re: Bad Smell from Old PCB Material ? It's that old familiar smell from my youth cutting and filing SRBP. And it smells even worse when it burns due to water going down the back of your old GEC TV when your watering the pot plants! Call me a sadist but I don't mind the smell its kind of comforting that not everything changes Cheers Mike T __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

1st May 2020, 10:55 am	#6
David G4EBT Dekatron Join Date: Feb 2003 Location: Cottingham, East Yorkshire, UK. Posts: 5,760	Re: Bad Smell from Old PCB Material ? The smell from drilling filing or sawing SRBP is phenol formaldehyde resin I believe, also used in the production of Bakelite. If I'm not mistaken, phenol is carbolic acid. There used to be a factory close to the M1 about Junction 28 - Chesterfield area and the phenolic smell was all pervading when driving past. I rather like the smell, but then I like the smell of felt tip markers and meths too, but don't make a habit of inhaling! (On the other hand, I can't abide the smell of bananas or hyacynths, so I guess well all have our sensitivities). This link is relevant: https://en.wikipedia.org/wiki/Phenol_formaldehyde_resin __________________ David. BVWS Member. G-QRP Club member 1339.

1st May 2020, 2:36 pm	#7
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,573	Re: Bad Smell from Old PCB Material ? Hi. I've noticed this too in recent years. As a youngster, I recall the smell of cutting and filing the dark SRBP and Veroboards but kind of liked it at the time and enjoyed the aroma as being part of the electronics hobby. Nowadays I find it overbearing and hate using it. I wondered if there was something going on making it outgas more now than when it was new. This kind of goes against the grain as generally the outgassing ought to become less over time. Then I started taking notice of other smells and odours which I never gave any attention to in the past. Any solvent paints, spirits, petrol, vehicle exhaust fumes, bonfires etc all seem very potent compared to years ago. I had learnt that the modern petrol does smell more these days if it has been hanging around in a can or lawn mower for a few months. I think it may be because of the ethanol that's added. My latest bugbear is the new workshop that I've recently built. The OSB floor and roof odours were too overbearing to work in there. After many months it is easing off but I still need to have the windows and door open to feel comfortable working in there. In my case, although I haven't been diagnosed, I believe I've developed an ultra sensitive sense of smell (hyperosmia). I try to avoid smelly chemicals now where possible or at least work outdoors, weather permitting. Regards, Symon.

1st May 2020, 5:20 pm	#8
Aub Nonode Join Date: Mar 2005 Location: Nuneaton, Warwickshire, UK. Posts: 2,037	Re: Bad Smell from Old PCB Material ? Thanks for all the replies, very interesting. I've used and cut fibreglass pcb loads of times, but not srbp. I only used it as I had a largish sheet of it id never used. Anyway, I've remade the front panel in aluminium. Cheers Aub __________________ Life's a long song, but the tune ends too soon for us all.

1st May 2020, 10:27 pm	#9
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,573	Re: Bad Smell from Old PCB Material ? I've sometimes wondered if it's in order to paint SRBP in order to seal it from the fumes. If it's OK to paint, then does anyone know what type of paint is safe to use? I suppose an oil based enamel paint would be suitable. I also wonder about using water based acrylics which are much safer generally. Regards, Symon