Spray Resist.

[John Stevenson 1Participant @johnstevenson1]

The spray stuff in cans.

How can it work, not how does it work.

Can I clean a plate of brass up, spray it with this stuff, let it dry, then burn the etched areas away with a laser the drop it into the ferric chloride ?

I need to get some quite small letters to stand proud of a brass sheet.

Don't mind buying a tin to try it IF it stands a chance of working, alternative is to use a spray can of paint and laser the etched area away.
Anyone done this or seen web sites where it has been done, need to use a laser as all the files are in the laser format.

[John Stevenson 1Participant @johnstevenson1]

[Nathan SharpeParticipant @nathansharpe19746]

John, have you looked on MadModder to see how Rob Wilson does his nameplates? Some excellent ferric chloride etching done by him, sharp and crisp edges.

Nathan.

[Nick_GParticipant @nick_g]

.

Ferric chloride and my mothers new stainless steel kitchen sink.!

The mere mention of that product even after all these years still brings back the memories dire mire I was in.

Nick

[Neil WyattModerator @neilwyatt]

Hi John,

You need to read my article in ME on how to do it

It works a treat, but a good even spray is what matters.

Don't a**e about with a laser, it will fail completely. You need a UV lightbox or (harder to get) sunshine.

or send me an email…

Neil

Edited By Neil Wyatt on 07/03/2015 08:35:28

[CotswoldsPhilParticipant @cotswoldsphil]

Hi John,

Here is a lasered cylinder's brass makers plate for my Minnie TE – still to be fitted. Depth is about 10 thou, difficult to see in the photo but is about scale and OK to take paint, but very crisp.

The input to the process was a vector graphic at 450dpi which was then used to drive a 10 watt laser etching machine, No masking, just 2 passes to achieve the depth, I've even got a cutting line. The smoke box and name plates were also done at the same time.

My understanding is that brass is difficult to process because it is so reflective. However, this was all done as an experiment when a company I work with was setting up a laser etching system. Recent information has revealed that masking the whole plate with a none reflective coating may be useful. I hope that the machine was not damaged in the process.

Regards

Phil

 

Edited By CotswoldsPhil on 07/03/2015 09:39:35

[Douglas JohnstonParticipant @douglasjohnston98463]

I have used the cans of resist for making printed circuit boards in the past but never liked it much. I found it difficult to get an even coating and the cans only had a shelf life of about a year. As the stuff is expensive I don't see any advantage in using it compared to ordinary paint when using a laser.

Doug

[Russell EberhardtParticipant @russelleberhardt48058]

Don't know about lasers but I find for flat brass dry film photoresist works well. Iron it on, expose to sunlight through ink jet printed master for 3 to 5 seconds here, develop in washing soda and etch.

Russell.

[Diane CarneyModerator @dianecarney30678]

I used the stuff for years and found it to be consistently inconsistent. Sometimes it works a dream and others it infuriates you to the point of screaming. The problem would seem to be the spray nozzles. Some allow a nice, fine covering and others dispense the stuff in blobs. It's just your luck what you get… really! You also need to be in as dust-fere an environment as you can achieve.
Don't forget, also, that photo resist has to be applied to the perfectly clean surface in safe light – i.e. yellow or, at least, a very poorly lit room. As Neil says, sunshine will effect exposure – if you can find any.
When I moved over to negative, film resist, life became much simpler and far less stressful.

Diane

[Neil WyattModerator @neilwyatt]

I used to know some electronics types.

There approach was to mount blank PCBs on a horizontal plate attached to an electric motor spinning reasonably fast, inside a cardboard box. No matter how inconsistent the spray, the debatable centrifugal force that doesn't exist spreads it nice and evenly.

Neil

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