The smell of SRBP

[IanBland]

I have a (whatever the opposite of fond is) memory of being about 20, staggering into work with the most terrible sickly hangover of my life, and having to spend the morning in a tiny workshop (sort of a large cubby hole with a bench) drilling holes in the stuff. It can never smell that strong again.

[Skywave]

Originally Posted by IanBland

I have a (whatever the opposite of fond is) memory of being about 20 . . .

Hmm. An antonym of the word 'fond' eh? 'Unfond'? No, seriously, how about 'rueful' - or possibly 'horrid' - or even 'hateful'.
Now please don't misunderstand me: I am not trying to 'score points' here ; I'm trying to be helpful. It's just this fascination I have with words in the English language.

Al.

[lesmw0sec]

Originally Posted by Philips210

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

Thanks - it took me down memory lane - I recall doing contract work for Flight Refueling many years ago and when ordering tufnol panels from stores, regardless of what was asked for, they used to issue that ghastly stuff - a blighter to cut & drill cleanly!

Les.

[kalee20]

Originally Posted by Skywave

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

No.

SRBP is cheaper, and probably takes punched holes better. SRBF machines better.

Within each product type, there are variations - resin types, fabric weave (coarse or fine), fabric type (cotton, linen, asbestos, glass-fibre), shape (flat or round).

Tufnol were interesting with their type names - birds, reptiles, fish, mammals. There's kite brand, heron brand, adder brand, asp brand, carp brand, vole brand, whale brand. Then they went all boring and called them by numbers (Tufnol 6F/45, epoxy resin, fine cotton weave-fibre)

[G6Tanuki]

The smell may be attractive to some (and offensive to others) but be aware that the fine dust produced when cutting/drilling/sanding it is really Doubleplusungood to inhale.

(same goes for the dust when working MDF: joinery-factory workers have significantly higher rates of upper-respiratory-tract malignancies).

The nasty carcinogenic bit is from the resins used in the bonding. The micro-abrasive and irritant nature of the dust-particles only helps to get them further into the cells to do their evil work.

[Philips210]

Hi

G6Tanuki makes some very good points there. I always knew it wasn't good to inhale the dust from SRBP but I originally found the aroma of the substance quite pleasant. Over the years I find the smell of it has become unbearable so when doing repairs to old PCBs I try to ensure good ventilation when soldering etc.

Regards
Symon

[Restoration73]

The smell from BRC boards relates to the red or green resist coating applied after
etching. SRBP will always have smell characterised by it being porous, except when
there is a waterproof lacquer coat used in marine equipment.
By comparison, fibreglass pcb only emits a smell when drilled or when there has been
overheating at a component location, e.g. wirewound resistor.

[Biggles]

I don't mind the smell at all. It takes me back to the early days of building projects on Veroboard. Wonderful invention. I must have used acres of the stuff over the years and still use it. The type with no tracks is good too, particularly for RF work. You can make a pseudo PCB with the bare type, using point to point wiring underneath. The older board was always darker in colour, and to be totally pedantic, I still try and use the darker board for older projects when I can find it. Remember the old Veroboard with the wider spaced holes? 0.2" spacing? Trouble is with SRBP is that it can warp when in larger sheets.
Alan.

[Philips210]

Hi.

Yes the plain Veroboard/stripboard (matrix board) is very useful and I've built many projects using this. Besides the commonly available 0.1" there was the 0.2" version as Biggles mentioned. There was also a 0.15" pitch version which is hard to find these days. I built the Proton Magnetometer from Practical Electronics October 1970 which specified 0.15" matrix board.

Regards
Symon

[emeritus]

That reminds me that when I was at Plesseys, one of the engineers used a large sheet of Veroboard to make an electric heater for his photographic print developing dish by linking alternate pairs of Veroboard tracks so that the copper strips were electrically all in series in a serpentine configuration. Inspired by this, another engineer used the technique to electrically heat his cat's basket, making use of the flexibility of large sheets by fitting a microswitch underneath the middle of the Veroboard so that it only heated up when the cat sat on it. This was in the days before central heating became the norm.

[G6Tanuki]

Originally Posted by Biggles

The type with no tracks is good too, particularly for RF work. You can make a pseudo PCB with the bare type, using point to point wiring underneath. .

In times-past I did a lot of work using 0.15-inch pitch plain 'perfboard' slabs with square-section pins fired through from behind where needed. The pins then took wire-wrap interconnects.

The "slabs" terminated in a double-sided PCB-style plated flat set of 'pins' that slotted into a suitable wafer-style edge socket so you could fit a few dozen such boards in a 19-inch chassis. . Think of it as a sort-of freestyle version of the old DEC "Flip-chip"

https://en.wikipedia.org/wiki/Flip_C...8PDP_module%29

approach. Wire-wrap was a really good way to do prototyping and near-to-production stuff - in many ways still more reliable than etched-PCBs-and-soldering, particularly when you needed to make a few dozen iterations of wiring and component placement on a single board.

[Skywave]

Originally Posted by G6Tanuki

The nasty carcinogenic bit is from the resins used in the bonding. The micro-abrasive and irritant nature of the dust-particles only helps to get them further into the cells to do their evil work.

Sounds familiar: reminds me of the current concerns about asbestos, which years ago I do believe was not recognised as the health hazard that it is today. So, in years to come, are we going to see a repetition of such a scare concerning those materials - now in common use - that contain those aforesaid resins? From what G6Tanuki has stated, that seems likely. So on that basis, why aren't the appropriate heath authorities addressing that concern now?
All a bit concerning.

Al.

[Peter.N.]

I quite like the smell, but even in the '50s they must have been aware of the dangers as the aforementioned laminating room had a large extractor fan in the wall at the far end and double doors at the entrance, the air movement was such that it kept the doors partly open.

Peter

[Radio Wrangler]

Not the same thing at all, but related.
SRBP is Synthetic Resin Bonded Paper. Simply paper soaked in a thermosetting resin , compressed in a mould and heated until it's set hard.
SRBF Synthetic ResinBonded Fabric is cloth soaked in a thermosetting resin and compressed ina mould, then heated.

SRBF was always more expensive and available in several grades (fine-ness of weave of cloth) The grades had cute names "Kite brand" "Mole Brand" and snails made a showing too. SRBP crumbled under stress, SRBF was much tougher with its oriented fibres.

SRBF was probably the first engineering composite. It got used in flat sheets and rods as moulded, but it also got machined. BA threaded screws would hold in tapped holes.

David

[Refugee]

SRBF was used in "posh" equipment and was less often seen by TV engineers in its day.
I have found a couple of photo resistors housed in SRBF blocks so that we can all see what the material looks like.

[Skywave]

SRBP & SRBF: I asked about the difference: comprehensive replies received. Thank you.

Al.