Hasselblad A12 back - 'Brushing up' light seal?

Forum statistics

Threads
198,994
Messages
2,784,305
Members
99,763
Latest member
bk2000
Recent bookmarks
0

Twotone

Member
Joined
Mar 20, 2023
Messages
167
Location
UK
Format
Multi Format
Hi folks,

I've got a few A12 backs for my 500C/M that need the light trap seals changing.

This consists of the foam strip that sits within a folded bit of 'foil' which is some sort of plastic and then a separate 'woven' seal that sits in a groove on the rear of the 'face plate'.

I've got a few kits coming which include both seals, but after speaking to a few different Hasselblad technicians, I've established that the thin 'woven' seal doesn't always need changing as often and can be 'brushed up'.

Before I get a stiff bristled brush and persuade the seal to 'stand up', is anyone aware of the appropriate method beyond what I'm suggesting?

Thanks,
TT
 

Axelwik

Member
Joined
Apr 6, 2023
Messages
302
Location
Albuquerque
Format
Large Format
Wasted film and time is more valuable than a few dollars in parts, but the only parts I ever change are the plastic/foil piece and foam. And the parts from Hasselblad are just as cheap as the aftermarket.

While you're waiting you can put a piece of black electrical tape over the darkslide slot to prevent light leaks, and just leave it on. The darkslide doesn't need to be inserted to change film - can be done right on the camera without removing the back. I see so many newbies taking the back off to change film - it's a lot easier to fumble around with two things rather than three (four when you count the film)!
 

Alex Varas

Subscriber
Joined
Mar 24, 2018
Messages
817
Location
Bilbao
Format
Medium Format
I think their assumption is correct. For me if looking at the front plate horizontally I can see the seal coming up a bit, no need to change it. Brushing up works fine as it works in older light seals in cut plate holder.
 
OP
OP

Twotone

Member
Joined
Mar 20, 2023
Messages
167
Location
UK
Format
Multi Format
I think their assumption is correct. For me if looking at the front plate horizontally I can see the seal coming up a bit, no need to change it. Brushing up works fine as it works in older light seals in cut plate holder.

Thanks for this - is there any particular method or brush type suggested?
 
OP
OP

Twotone

Member
Joined
Mar 20, 2023
Messages
167
Location
UK
Format
Multi Format
Wasted film and time is more valuable than a few dollars in parts, but the only parts I ever change are the plastic/foil piece and foam. And the parts from Hasselblad are just as cheap as the aftermarket.

While you're waiting you can put a piece of black electrical tape over the darkslide slot to prevent light leaks, and just leave it on. The darkslide doesn't need to be inserted to change film - can be done right on the camera without removing the back. I see so many newbies taking the back off to change film - it's a lot easier to fumble around with two things rather than three (four when you count the film)!

I absolutely agree, I wouldn't cheap out for the sake of it!

Thanks for the suggestion.
 

mshchem

Subscriber
Joined
Nov 26, 2007
Messages
14,692
Location
Iowa City, Iowa USA
Format
Medium Format
You need to change the foam in the seal. To do this you need to disassemble. If the flexible plastic is still good I suppose you could find foam??

Brushing just gets rid of the powdered dried out foam, doesn't solve the light leak.

Easy and fast, load film, install back, pull dark slide, cover slot with a couple layers of black electrical tape.

I would just replace the seals. I'm a bit shaky and I can do it.
 
OP
OP

Twotone

Member
Joined
Mar 20, 2023
Messages
167
Location
UK
Format
Multi Format
You need to change the foam in the seal. To do this you need to disassemble. If the flexible plastic is still good I suppose you could find foam??

Brushing just gets rid of the powdered dried out foam, doesn't solve the light leak.

Easy and fast, load film, install back, pull dark slide, cover slot with a couple layers of black electrical tape.

I would just replace the seals. I'm a bit shaky and I can do it.

Hi there,

I'm not talking about the flexible plastic or the foam seal, I'm talking the separate thin woven seal.

Im happy to change it, but the reason for this thread is because two different ex-Hasselblad technicians have informed me it doesn't need changing each time the foam seal is changed, and can instead be 'brushed up'.

The purpose of my post was to understand the particular method in which people use to brush it up but I'm just going to have a go and see.

Thanks
 

mshchem

Subscriber
Joined
Nov 26, 2007
Messages
14,692
Location
Iowa City, Iowa USA
Format
Medium Format
Hi there,

I'm not talking about the flexible plastic or the foam seal, I'm talking the separate thin woven seal.

Im happy to change it, but the reason for this thread is because two different ex-Hasselblad technicians have informed me it doesn't need changing each time the foam seal is changed, and can instead be 'brushed up'.

The purpose of my post was to understand the particular method in which people use to brush it up but I'm just going to have a go and see.

Thanks

Got it! I would start with a stiff toothbrush. I've not had problems with, what I call "felt" seals, at least not that I know of. I have a couple small brass brushes that could maybe work.

Now that I know what you are doing, I'm going to be checking my A-12 magazines 😁
 

itsdoable

Member
Joined
Aug 26, 2013
Messages
825
Location
Canada
Format
Medium Format
The velvet strip does not need to be replaced unless it looks bald. Most aftermarket kits (like the one listed above) do not come with the velvet strip, Hasselblad OE kits do.

The Hasselblad OE seals use a metal foil instead of plastic. The metal foils last forever (unless you accidentally fold/wrinkle them) and you can just scrape the old foam off, and cut some replacement foam for them. It's the foam that deteriorates. But the aftermarket plastic kits work fine and are inexpensive.
 
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links.
To read our full affiliate disclosure statement please click Here.

PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Ilford ADOX Freestyle Photographic Stearman Press Weldon Color Lab Blue Moon Camera & Machine
Top Bottom