The smell of SRBP - UK Vintage Radio Repair and Restoration Discussion Forum

Philips210 · 11th Feb 2017, 9:36 pm

Hi.

We all know how to recognise the smell of SRBP or the trade names of this material such as Paxolin or Tufnol. I've always found the darkest circuit board or Veroboard to give off the strongest smell especially if it's drilled or filed etc.

What is apparent to me is that it seems to be much more potent than it used to be. Even unused NOS board reeks. I'm sure it wasn't as strong smelling when it was purchased new 30 to 40 years ago. I wonder if something chemically is going on, perhaps the resin may be reacting with the atmosphere in some way.

The very light SRBP board generally doesn't smell so much but I've found some NOS pieces that are smelling quite strong. Perhaps it's me having a sensitive nose but as I say I'm sure it never smelled as powerful as this when it was new.

On a similar note, the circuit boards used in many BRC sets reek quite badly. When I was in the repair business, I never really noticed the smell of the circuit boards too much. Nowadays, repairing say a Ferguson transistor radio from the early 1970's or a BRC 3000 TV from the same period, the smell given off by the circuit board is quite strong. I always wear gloves as it's a struggle to get the smell off your hands. I wonder if it is a combination of the circuit board reacting not only with the air but also with the post solder flux removing chemical. Again it didn't seem so apparent when repairing the equipment when it was within it's service life. So it would seem to be a time related condition.

Has anyone else noticed this?

Regards
Symon.

thermionic · 11th Feb 2017, 10:32 pm

Hi Symon.

Perhaps it's just the fact that we don't encounter it everyday as we did when repairing sets in on a daily basis?

I've just been building circuits on stripboard, and it stinks!

SimonT

Philips210 · 11th Feb 2017, 11:02 pm

Hi Simon.

You could have a point there. I do remember in many instances it was possible to name the manufacturer by the smell of the equipment. Some of the Japanese audio equipment from the 1970's seemed to have a similar smell to an electrolytic capacitor that had let go, quite a horrible chemical smell. I also recall a HiFi shop in the mid 1970's the said aroma could be quite unbearable if all the windows were closed and the heating was on. It was probably the production line chemical used to clean the assembled PCBs.

Regards
Symon.

Stylo N M · 11th Feb 2017, 11:56 pm

Hi,

i soppose we also may be noticing these oders more now, since our cars and many other things, have beacome much more cleaner running, and have cleaner air.

In earlier times many more people smoked, so the smell of people smoking, and an open coal fire burning in the grate, dad with his pipe or cigars, would all be surficient, to adiquatly drown out the smell of the pariffin stove in the other room, and mums cake baking in the kitchen, so the paxolin circuit board would be way down the list.

It would be more likley to be something, that would be more noticable, in a TV and radio repair shop than in the home.

Paul.

Tom_I · 12th Feb 2017, 12:08 am

For anyone (like me) who gets mildly annoyed by people talking in abbreviations without explaining them, SRBP is "synthetic resin bonded paper", a composite material made of paper impregnated with phenol formaldehyde resin, used in the manufacture of printed circuit boards.

Sorry, I mean PCBs.

Refugee · 12th Feb 2017, 1:08 am

I think it is down to the resin used.
Older boards would have been made with coal tar based resin and later ones with oil that has been purified a bit more.
We were all used to it as homes almost always has something electronic that would keep us used to the smell.
For the past couple of weeks we have been blessed with memories of old chemicals as the local council have been digging up the floor slab of an old coal tar plant.
It smelt of vintage weed killer for several miles in all directions while they were loading all the spoil up and taking it away.

Ed_Dinning · 12th Feb 2017, 8:08 am

Hi Gents, less cigarettes smoked and sense of smell now keener?

Ed

evingar · 12th Feb 2017, 9:21 am

It's certain the case in pubs. The fag smoke covered up even more unpleasant pongs.

Philips210 · 12th Feb 2017, 10:31 am

Quote:

Originally Posted by Tom_I

For anyone (like me) who gets mildly annoyed by people talking in abbreviations without explaining them, SRBP is "synthetic resin bonded paper", a composite material made of paper impregnated with phenol formaldehyde resin, used in the manufacture of printed circuit boards.

Sorry, I mean PCBs.

Hi.

People do use abbreviations for long terms such as synthetic resin bonded paper as it's a quick way to express it. I don't see the need to have to explain what recognised abbreviations mean everytime I use them otherwise what's point of using an abbreviation then explaining what it means! Abbreviations are there for a purpose.

Sorry to have annoyed you.

Regards
Symon.

Philips210 · 12th Feb 2017, 12:46 pm

Hi.

Some good points made from above members. It's probably true that due to the lack of smoking these days then it will be easier to detect any extraneous odours given off by equipment. I also notice the smell given off of voltage droppers, particularly new ones, can induce an irritable cough.

I still wonder if the smell will worsen over time. As member threeseven points out in this thread https://www.vintage-radio.net/forum/...009#post918009 post#7 plastic can alter it's characteristics over time so wondered if something could be happening to the SRBP. Perhaps a chemist may know if this is the case.

Regards
Symon

dseymo1 · 12th Feb 2017, 1:20 pm

I rather like the smell - it's a reminder of the days of high street component and surplus shops, as is the smell of the varnish on ex-WD gear.

fetteler · 12th Feb 2017, 1:25 pm

Yeah, I like the smell too

Takes me back to happier, cosier times spending my school holidays and evenings soldering away on whatever the current project was.

Steve.

Peter.N. · 12th Feb 2017, 1:46 pm

I used to maintain the PA system in a paper mill in the '50s, they had a room called the 'laminating room' where a group of girls assembled circles of resin coated thin card into stacks and the stacks onto trays that went into a hot press, I can still remember that smell and its pretty well the same as laminated board now, so I don't think the resin has changed much.

The finished result was for pit prop caps - takes you back a bit.

Peter

Skywave · 12th Feb 2017, 2:13 pm

SRBP: silicon resin bonded paper; SRBF: silicon resin bonded fibre. Same substance?

Al.

Andrew B · 12th Feb 2017, 2:19 pm

I have an agricultural chemical manufacturer close by, when the wind is in the wrong direction, I get a whiff of phenol drifting over.

fetteler · 12th Feb 2017, 2:30 pm

Quote:

Originally Posted by Skywave

SRBP: silicon resin bonded paper; SRBF: silicon resin bonded fibre. Same substance?

SRBF - synthetic resin bonded fabric... Tufnol

Steve.

lesmw0sec · 12th Feb 2017, 2:47 pm

Diverging a little, does anyone recall a brand of the stuff known as 'Kite'? Horrible stuff to work and if you guillotined it, the edge would crumble horribly.

Philips210 · 12th Feb 2017, 3:59 pm

Hi Les.

Yes I recall that name and just checked, it's part of the Tufnol range http://www.tufnol.com/materials-full...ard-sizes.aspx

Regards
Symon.

Philips210 · 12th Feb 2017, 4:05 pm

In my case SRBP could mean Smells Right B****y Pungent

Symon

Skywave · 12th Feb 2017, 6:54 pm

Fetteler: thank you for that correction. So SRBP and SRBF are not quite the same substance, then?

Al.

11th Feb 2017, 9:36 pm	#1
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,573	The smell of SRBP Hi. We all know how to recognise the smell of SRBP or the trade names of this material such as Paxolin or Tufnol. I've always found the darkest circuit board or Veroboard to give off the strongest smell especially if it's drilled or filed etc. What is apparent to me is that it seems to be much more potent than it used to be. Even unused NOS board reeks. I'm sure it wasn't as strong smelling when it was purchased new 30 to 40 years ago. I wonder if something chemically is going on, perhaps the resin may be reacting with the atmosphere in some way. The very light SRBP board generally doesn't smell so much but I've found some NOS pieces that are smelling quite strong. Perhaps it's me having a sensitive nose but as I say I'm sure it never smelled as powerful as this when it was new. On a similar note, the circuit boards used in many BRC sets reek quite badly. When I was in the repair business, I never really noticed the smell of the circuit boards too much. Nowadays, repairing say a Ferguson transistor radio from the early 1970's or a BRC 3000 TV from the same period, the smell given off by the circuit board is quite strong. I always wear gloves as it's a struggle to get the smell off your hands. I wonder if it is a combination of the circuit board reacting not only with the air but also with the post solder flux removing chemical. Again it didn't seem so apparent when repairing the equipment when it was within it's service life. So it would seem to be a time related condition. Has anyone else noticed this? Regards Symon.

11th Feb 2017, 10:32 pm	#2
thermionic Heptode Join Date: Apr 2003 Location: Cornwall, UK. Posts: 988	Re: The smell of SRBP Hi Symon. Perhaps it's just the fact that we don't encounter it everyday as we did when repairing sets in on a daily basis? I've just been building circuits on stripboard, and it stinks! SimonT __________________ The honesty of imperfection..........

11th Feb 2017, 11:02 pm	#3
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,573	Re: The smell of SRBP Hi Simon. You could have a point there. I do remember in many instances it was possible to name the manufacturer by the smell of the equipment. Some of the Japanese audio equipment from the 1970's seemed to have a similar smell to an electrolytic capacitor that had let go, quite a horrible chemical smell. I also recall a HiFi shop in the mid 1970's the said aroma could be quite unbearable if all the windows were closed and the heating was on. It was probably the production line chemical used to clean the assembled PCBs. Regards Symon.

11th Feb 2017, 11:56 pm	#4
Stylo N M Heptode Join Date: Jul 2012 Location: Derby DE1, Derbyshire, UK. Posts: 626	Re: The smell of SRBP Hi, i soppose we also may be noticing these oders more now, since our cars and many other things, have beacome much more cleaner running, and have cleaner air. In earlier times many more people smoked, so the smell of people smoking, and an open coal fire burning in the grate, dad with his pipe or cigars, would all be surficient, to adiquatly drown out the smell of the pariffin stove in the other room, and mums cake baking in the kitchen, so the paxolin circuit board would be way down the list. It would be more likley to be something, that would be more noticable, in a TV and radio repair shop than in the home. Paul.

12th Feb 2017, 12:08 am	#5
Tom_I Heptode Join Date: Jul 2006 Location: North Herts. UK. Posts: 549	Re: The smell of SRBP For anyone (like me) who gets mildly annoyed by people talking in abbreviations without explaining them, SRBP is "synthetic resin bonded paper", a composite material made of paper impregnated with phenol formaldehyde resin, used in the manufacture of printed circuit boards. Sorry, I mean PCBs.

12th Feb 2017, 1:08 am	#6
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: The smell of SRBP I think it is down to the resin used. Older boards would have been made with coal tar based resin and later ones with oil that has been purified a bit more. We were all used to it as homes almost always has something electronic that would keep us used to the smell. For the past couple of weeks we have been blessed with memories of old chemicals as the local council have been digging up the floor slab of an old coal tar plant. It smelt of vintage weed killer for several miles in all directions while they were loading all the spoil up and taking it away.

12th Feb 2017, 8:08 am	#7
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,194	Re: The smell of SRBP Hi Gents, less cigarettes smoked and sense of smell now keener? Ed

12th Feb 2017, 9:21 am	#8
evingar Octode Join Date: Oct 2003 Location: Newbury, Berkshire, UK. Posts: 1,770	Re: The smell of SRBP It's certain the case in pubs. The fag smoke covered up even more unpleasant pongs. __________________ Chris

12th Feb 2017, 12:46 pm	#10
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,573	Re: The smell of SRBP Hi. Some good points made from above members. It's probably true that due to the lack of smoking these days then it will be easier to detect any extraneous odours given off by equipment. I also notice the smell given off of voltage droppers, particularly new ones, can induce an irritable cough. I still wonder if the smell will worsen over time. As member threeseven points out in this thread https://www.vintage-radio.net/forum/...009#post918009 post#7 plastic can alter it's characteristics over time so wondered if something could be happening to the SRBP. Perhaps a chemist may know if this is the case. Regards Symon

12th Feb 2017, 1:20 pm	#11
dseymo1 Retired Dormant Member Join Date: Dec 2007 Location: Shropshire, UK. Posts: 3,051	Re: The smell of SRBP I rather like the smell - it's a reminder of the days of high street component and surplus shops, as is the smell of the varnish on ex-WD gear.

12th Feb 2017, 1:25 pm	#12
fetteler Octode Join Date: Jul 2011 Location: Staffordshire Moorlands, UK. Posts: 1,474	Re: The smell of SRBP Yeah, I like the smell too Takes me back to happier, cosier times spending my school holidays and evenings soldering away on whatever the current project was. Steve. __________________ Those who lack imagination cannot imagine what is lacking...

12th Feb 2017, 1:46 pm	#13
Peter.N. Dekatron Join Date: Jul 2008 Location: Charmouth, Dorset, UK. Posts: 3,601	Re: The smell of SRBP I used to maintain the PA system in a paper mill in the '50s, they had a room called the 'laminating room' where a group of girls assembled circles of resin coated thin card into stacks and the stacks onto trays that went into a hot press, I can still remember that smell and its pretty well the same as laminated board now, so I don't think the resin has changed much. The finished result was for pit prop caps - takes you back a bit. Peter

12th Feb 2017, 2:13 pm	#14
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: The smell of SRBP SRBP: silicon resin bonded paper; SRBF: silicon resin bonded fibre. Same substance? Al.

12th Feb 2017, 2:19 pm	#15
Andrew B Heptode Join Date: May 2015 Location: Bradford, West Yorkshire, UK. Posts: 512	Re: The smell of SRBP I have an agricultural chemical manufacturer close by, when the wind is in the wrong direction, I get a whiff of phenol drifting over. __________________ worried about the electrons entering the circuit and the smoke leaving Andrew

12th Feb 2017, 2:47 pm	#17
lesmw0sec Octode Join Date: Jul 2009 Location: Carmel, Llannerchymedd, Anglesey, UK. Posts: 1,506	Re: The smell of SRBP Diverging a little, does anyone recall a brand of the stuff known as 'Kite'? Horrible stuff to work and if you guillotined it, the edge would crumble horribly.

12th Feb 2017, 3:59 pm	#18
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,573	Re: The smell of SRBP Hi Les. Yes I recall that name and just checked, it's part of the Tufnol range http://www.tufnol.com/materials-full...ard-sizes.aspx Regards Symon.

12th Feb 2017, 4:05 pm	#19
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,573	Re: The smell of SRBP In my case SRBP could mean Smells Right B****y Pungent Symon

12th Feb 2017, 6:54 pm	#20
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: The smell of SRBP Fetteler: thank you for that correction. So SRBP and SRBF are not quite the same substance, then? Al.