Etching

Kevin

Letroset, I believe did do tracks for the simple production of pcbs. The transfers were rubbed onto cleaned copper board and would resist the attack of ferric chloride that would dissolve the copper.

So perhaps the letters will do better then you think.

There are means of using UV light and photo etch resist to form the resist on materials.

The negative/positive can be generated by a laser and possibly inkjet printer on to acetate sheets.

-- Cheers Adrian.

Kevin,

Maplin sell a spray photoresist for pcbs

Andrew Mawson Bromley, Kent

Don't be too ready to dismiss the ME article providing you only need alphanumeric characters and straight lines. Though obtaining Letraset in the right fount and typeface might be a problem now The author of that old ME article (Rex Tingay was it ?) describes what will work very well providing you follow his directions exactly. I've had good success with his method on brass and copper and the results are an order of magnitude cheaper than purchasing them from a certain mail order specialist.

If you are going to do a few items only you may do it yourself but be warned: It takes a lot of time and effort and your first etchings will probably be useless.

Take a look at Randy Gordon-Gilmore's site at

I did some etching myself but found that the quality of the did not live up to my expectations; I would have had to buy better (and more expensive) equipment. Instead I have my etchings made by Photo Etch Consultants in the UK.

Have a look at

and

Take a look at:

Just what you need I believe....

Cheers, Jon.

Kev> Can anyone point me to some resources for etching metals (like for

When I last used Letraset for PCBs, we used to put the Letraset onto clear acetate, then use this to make a "contact print" onto a photosensitive copper clad board. The photo resist was developed in sodium hydroxide IIRR, and then the board etched in a mix of hydrochoric acid and hydrogen peroxide. Anyway, I believe you can buy the photoresist as an aerosol.

If you print two masters onto an inket transparency, then overlay them to increase the ink density you can just use your favourite DTP package instead of Letraset.

Martin L

If access to a laser printer and transparencies is possible, one layer should be enough.

Mark Rand RTFM

It seldom is, and edges are fuzzy.

Draw and print at higher resolution, I regularly make PCB's using overhead transparencies, sometimes laser, sometimes ink jet, with both I can easily do neat 0.005 lines. You need to produce the output as WMF's or EMF's, or some other vector format file, use bmp's or jpegs and the edges will be fuzzy.

-- Steve Blackmore

If you have a Laser printer try Press and Peel from Maplins. Using any program to generate the graphics you want you print hem onto press and peel, remember to flip them first, then iron onto your metal. The toner is microscopic graphite particles wrapped in thermoplastic, as you iron the reversed image onto the metal sheets it re-melts the plastic onto the metal which forms the barrier for etching. I have successfully used it to make printed circuit boards and to etch model tram sides out of brass.

I had some correspondence with this chap in Finland about etching metal. I think you'll agree his photos of locos are worth seeing too.

Bill

I used to do pcbs back in the 70's. The Letraset stuff was a bit iffy AFAIR. It would sometimes peel away if the copper was not absolutely clean and also if the Letreset was slightly old.

I'd try one of the photographic kits, do an acetate on a PC printer and develop between a couple of glass plates in the sunlight. Don't etch too quickly or you'll get an 'undercut' especially if there's thin lines.

Incidentally it tends to be sensitive to temperature, both in getting the right thickness on the metal before exposure and temperature of the etchant

Kodak at the time used to sell a UV develop photo resist either as a positive or negative etch, and we finally used that as we were doing .005" bars on .005" steel shim for Moire fringe gratings. I think that was taking it to the limit and we finally settled for a .002" etch and used reflective infra red sensors.

Mart

In message , Dick Scratcher writes