"Laser Marking with Moly"

[Colin Cooper]

Article suggesting a cheaper method for lasermarking steel:
http://www.adafruit.com/blog/2013/08/13/laser-marking-with-moly/

RS & Farnell appear to stock it for ~£15

Is there any reason it shouldn't be tried with our cutter?

[Russ Garrett]

It's worth a try. The only real concern is fumes coating the inside of
the machine, so just be careful.

Russ

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Russ Garrett
ru...@garrett.co.uk

[pad...@padski.co.uk]

I have tried this... With various powers and speeds on steel, and in every case it wiped clean off leaving no trace.  It was using dry moly from rs.
Perhaps you will discover the secret :)
Paddy

Sent from my thing.

[Alex Beckett]

So has anyone tried the Cermark type sprays for cheaper on eBay?

http://www.ebay.co.uk/itm/LASER-MARKING-ENGRAVING-SPRAY-LIKE-CERMARK-WORKS-ON-ALL-METALS-400ml-/221227959277?pt=LH_DefaultDomain_3&hash=item338236c3ed

Tempted to get some for the space, put a tin next to it and ask people to pay if they use it. 

[Colin Cooper]

This seems to be the thread referenced from the adafruit article 

The most relevant comment is the following ( my highlighting):

 

It's actualluy a pottery glaze and its a Molybdenum sulphide. There are alternatives to it if you are willing to try re-inent the wheel. 
The trick is to apply it evenly and thinly - an airbrush with a gravity feed hopper works well. We usea a paasche with a no 5 needle. We tried a jar feed , but it clogs.
The big problem is that this type of marking relys on heat to bond , and large objects wick away heat fast if you have a largeish object you lasering. The problem with using much slower speeds with these type compounds is that too much heat tends to "overburn" the stuff and leads to less resolution.
We have found that on big objects , warming them before coating and lasering works a charm , the stuff dries quicker and marks faster.
We use distilled water with a drop or 2 of dishwashing liquid to act as a wetting agent to dilute the compound prior to airbrushing and also reclaim the excess on the object We wash off into a container and then periodically boil off the water and re use the powder.
We do have an alternative in South Africa , it costs $75 for 1/2 a pound but it doesnt work as well as Cerdec/Thermark and doesnt stick nicely.
We clean ALL objects with either beziene or alcohol prior to applying the compound.
What we have found is that these compounds can "stain" the objects , After washing off , you can sometimes plainly see where the coating was , so we dont pre-apply the compound and leave it for later lasering , we have found that the best way is to apply, laser and remove as quickly as possible.

I'd like to be able to mark metals, but don't have a current requirement.  £15 seems ok for an experiment (which Paddy has already tried).  I'm not sure I'd like to spend £45 or £100+ without a fair chance of success.

 

On 14 August 2013 12:51, Alex Beckett <ai3...@googlemail.com> wrote:
So has anyone tried the Cermark type sprays for cheaper on eBay?
http://www.ebay.co.uk/itm/LASER-MARKING-ENGRAVING-SPRAY-LIKE-CERMARK-WORKS-ON-ALL-METALS-400ml-/221227959277?pt=LH_DefaultDomain_3&hash=item338236c3ed
Tempted to get some for the space, put a tin next to it and ask people to pay if they use it. 

On Wednesday, 14 August 2013 11:24:08 UTC+1, PaddyD wrote:
I have tried this... With various powers and speeds on steel, and in every case it wiped clean off leaving no trace.  It was using dry moly from rs.
Perhaps you will discover the secret :)
Paddy
Sent from my thing.
----- Reply message -----
From: "Russ Garrett" <ru...@garrett.co.uk>
To: "London Hack Space" <london-h...@googlegroups.com>
Subject: [london-hack-space] "Laser Marking with Moly"
Date: Wed, Aug 14, 2013 11:03

It's worth a try. The only real concern is fumes coating the inside of
the machine, so just be careful.
Russ
On 13 August 2013 19:59, Colin Cooper <cdcoo...@googlemail.com> wrote:
>
> Article suggesting a cheaper method for lasermarking steel:
> http://www.adafruit.com/blog/2013/08/13/laser-marking-with-moly/
>
> RS & Farnell appear to stock it for ~£15
>
> Is there any reason it shouldn't be tried with our cutter?
>
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> You received this message because you are subscribed to the Google Groups "London Hackspace" group.

> For more options, visit https://groups.google.com/groups/opt_out.
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Russ Garrett
ru...@garrett.co.uk

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