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-   -   Dalo Pen replacement (https://www.vintage-radio.net/forum/showthread.php?t=168708)

Colin Boggis 5th Jul 2020 10:43 am

Dalo Pen replacement
 
1 Attachment(s)
Like many others I've been disappointed with several of the current offerings as Dalo replacements. I have found most, particularly those that are actually "permanent markers" do not prevent etchant damaging (pitting) the wanted copper areas and this is a big problem on very fine tracks. Even the Cif etchant resist pen sold by CPC Farnell is not totally reliable.
I believe I have at long last found a true Dalo replacement - it's called "Pen-touch" and is a paint(not ink) pen. It's available in several widths from Amazon.
I find the fine tip best as it allows the drafting of narrow tracks and larger areas can be filled in if needed. This is a pump action pen with a plastic tip, not just hole at the end of a narrow metal tube. It doesn't run and the paint is quite dense.
Not very expensive either £4.99 including post.
See attached picture.

Bazz4CQJ 8th Jul 2020 6:48 am

Re: Dalo Pen replacement
 
Interesting; I've still got one or two Dalos in my secret place, but cannot count on them seeing me out. That particular pen appears to be widely available; I don't buy from the site you mention.

What are you using to clean it off (acetone)?

B

wireless_john 13th Jul 2020 6:52 pm

Re: Dalo Pen replacement
 
That's good to know. I have a couple of original Dalo pens that are still working but I don't know for how much longer!

John

wireless_john 14th Jul 2020 9:12 pm

Re: Dalo Pen replacement
 
I have just made a small PCB with a Sharpie pen. It was surprisingly good! I was mentally prepared to have to do it again with a Dalo pen, but no, it was OK.

The Pen-touch sounds good though, especially for fine lines so I'll be ordering one of those for the next one I make.

John

Oldcodger 25th Aug 2020 10:21 pm

Re: Dalo Pen replacement
 
Two solutions( possibly three) I've found
1- sharpie.
2- most permanant markers.
3- Nail varnish, but years ago some firms brought out a nail varnish pen ,similar to a permanant marker. I've seen them advertised on line. Might be worth a look.

Colin Boggis 30th Aug 2020 8:14 pm

Re: Dalo Pen replacement
 
Sorry for late reply, but for Bazz4CQJ - yes I use acetone. I've used this pen several times now and it is just as good as the Dalo was, but it is possible to get a blob if you pump it too often so needs a little care.

Philips210 30th Aug 2020 8:26 pm

Re: Dalo Pen replacement
 
Quote:

Originally Posted by Bazz4CQJ (Post 1267660)
What are you using to clean it off (acetone)?

B

Hi.

I have used acetone to remove the dried ink which works well.

Years ago I tried an experiment. White spirit was tried with poor results. Next methylated spirits sort of worked but not too well. Then I put some white spirit and some meths together on a cloth. It worked quite well but the somewhat oily residue from the white spirit had to be washed off with detergent. Interesting that combining the two gave improved results.

Regards,
Symon

MrBungle 30th Aug 2020 9:12 pm

Re: Dalo Pen replacement
 
I've skipped using pen and ink now. The thing that ended up working for me is quite fiddly but works well.

1. Get Tamiya masking tape
2. Clean the board with a pan scourer and let it dry
3. cover it with the tape, overlapping slightly.
4. Draw the design on the masking tape with any old pen (bonus it doesn't get finger prints on it now)
5. carefully cut round the traces with a scalpel and peel the rest off.
6. Etch as usual.

The tape doesn't dissolve in ferric chloride and you get really sharp traces!

Bazz4CQJ 30th Aug 2020 10:40 pm

Re: Dalo Pen replacement
 
Hey Mr Bungle is back :). The masking tape is interesting...but I still have a few genuine Dalos in my secret place.

B

Philips210 31st Aug 2020 9:45 am

Re: Dalo Pen replacement
 
For not too complicated artwork then that's a good way to do it Mr Bungle. I'll purchase some of that Tamiya masking tape and give it a go.
I have before tried something similar using PVC insulation tape overlayed with masking tape which seemed to be OK too but is very dependent on the quality of the tape's adhesive. Some cheap tapes don't stick too well.
Why did I use two tapes? Well I didn't trust the masking tape to be etch resistant so the PVC tape seemed better but that alone was not ideal for marking out the design as it will smear as you progress drawing the lines. A layer of masking tape was then required over the top of the PVC. I used a fine tip standard Bic pen for marking out the design.

Regards,
Symon

Colin Boggis 5th Sep 2020 8:23 pm

Re: Dalo Pen replacement
 
Having sung the praises of the "Pen-Touch" I now have some reservation! Just nearly finished a layout when the whole "nib" fell out dumping paint all over the place. Had to clean off much of my work & start again with pen put back together. Finished layout OK but still concerned about that incident - I'll contact the supplier to see what they think ( if they care that is!). I'll update you all in due course.
The Tamiya tape idea is interesting - might give it a try.

Colin Boggis 7th Sep 2020 8:50 pm

Re: Dalo Pen replacement
 
Just for the record - when I told the supplier about the pen falling apart, they instantly apoligised & sent a replacement. So they do care! Good service and hopefully the failure was a one-off.

wireless_john 8th Oct 2020 7:23 pm

Re: Dalo Pen replacement
 
Colin, Just about to buy one of these - are you still happy with it? Is it acrylic paint?

John

wireless_john 21st Feb 2021 6:31 pm

Re: Dalo Pen replacement
 
I've just spent the afternoon making a PCB using a Sharpie as an etch resist. Second time I've used one and once again it worked as well as the old Dalo pens.

It's actually a little bit less messy in some ways. With a Dalo pen, if you pressed a bit too heavily, you could get a flood of ink all over your PCB. That's happened to me!

So, it's another YES from me for Sharpies!

John

Philips210 22nd Feb 2021 12:23 am

Re: Dalo Pen replacement
 
Hi.

I've found the Sharpie marker pens to be good too but stopped using them after feeling light-headed and unsteady. I was careful to avoid inhaling the fumes as well. Even out in the open the smell can be quite potent. I never experienced this with the old Dalo pens or the Rotring marker pens. There seems to be something in those Sharpie pens that disagrees with me so reluctantly won't be using them again.

Regards,
Symon

wireless_john 22nd Feb 2021 9:04 am

Re: Dalo Pen replacement
 
Thanks. I'll bear that in mind although I have to say I didn't notice that when I was using it.

John

marty_ell 23rd Feb 2021 10:14 am

Re: Dalo Pen replacement
 
Quote:

Originally Posted by Philips210 (Post 1344829)
Hi.

I've found the Sharpie marker pens to be good too but stopped using them after feeling light-headed and unsteady. I was careful to avoid inhaling the fumes as well. Even out in the open the smell can be quite potent. I never experienced this with the old Dalo pens or the Rotring marker pens. There seems to be something in those Sharpie pens that disagrees with me so reluctantly won't be using them again.

Regards,
Symon

You might like to take a look at Edding 8404 pens. They are excellent for laying down resist for fine, closely packed tracks. They draw easily between DIL pins, SOIC pins are easy; I have even on occasion used them to draw TSSOP pins (you need a steady hand for this !). They don't smell and have never caused me any health problems.

A few tips:
- although the 8404 resist appears to dry near-instantaneously then is dry enough to sustain finger pressure as you lay down other tracks - in fact they take some hours to cure fully. Best left overnight in a warm place. If you don't do this the resist will gradually lift off during etching and the copper will appear rough and pockmarked
- one pen is enough to do eg. a Eurocard full of chips. However as the pen becomes used up the flow rate decreases until you have to wait a few minutes for the nib to fully re-ink. Buy yourself two pens and swap them periodically to keep the ink flowing, or be prepared for frequent tea breaks
- storing them nib down for some hours before you start using them also helps
- don't have your etchant at too high a temperature as this may distort the resist. I never go above 'just too hot to touch'

For large copper areas I swear by parcel tape and Dalo 33 pens.
Cheers, Marty

Bazz4CQJ 23rd Feb 2021 1:55 pm

Re: Dalo Pen replacement
 
These pens made by Mitsubishi are very good https://www.ebay.co.uk/itm/Uni-Super...0AAOSwSCZbNM21 and were available in Wilko. Nice fine point and I like them very much just as general permanent markers, though my heart belongs to Dalo for PCB's (still got some) :).

B

G0HZU_JMR 23rd Feb 2021 6:08 pm

Re: Dalo Pen replacement
 
I just had a rummage and dug out my old Dalo pen. It must be at least 25 years old and I think I haven't used it since I made a PCB for my very first PIC programmer. However, I removed the end cap and tried it and it still works! It always gave really good edge definition when etching PCBs. A tough act to follow I think...

Philips210 23rd Feb 2021 10:52 pm

Re: Dalo Pen replacement
 
Quote:

Originally Posted by marty_ell (Post 1345244)
You might like to take a look at Edding 8404 pens.
Cheers, Marty

Hi Marty.

Thanks, I will purchase one and give it a try.

My late father obtained a number of the Japanese made Royal Sovereign Magic Marker pens which have a tip at each end (fine and coarse) They were excellent quality pens which I used for marking out sheet metal etc. I wonder if the composition of those pens would be suitable as an etch resist. I still have a few lying around so I'll do a few tests to check suitability.

Regards,
Symon

MrBungle 24th Feb 2021 9:44 pm

Re: Dalo Pen replacement
 
Meant to update this seeing as I last posted in here in August, far too long ago. I've disposed of my etching stuff and chemicals now. I'm usually only building one-offs so it is way too much work to take on with limited time and messy to boot. Since the last post I've done two dead bug boards on FR4 and one in Kicad which was shipped off to JLCPCB. Feet up on the desk and read a book for a couple of weeks!

On that subject, if anyone is interested I have a slightly rusty but fully working Mega LV202 UV box available FOC. PM me if you are interested. Will have to collect from SW London (I'll hold on to it until post-Covid)

David G4EBT 25th Feb 2021 11:27 am

Re: Dalo Pen replacement
 
5 Attachment(s)
Quote:

Originally Posted by MrBungle (Post 1345962)
Meant to update this seeing as I last posted in here in August, far too long ago. I've disposed of my etching stuff and chemicals now. I'm usually only building one-offs so it is way too much work to take on with limited time and messy to boot. Since the last post I've done two dead bug boards on FR4 and one in Kicad which was shipped off to JLCPCB. Feet up on the desk and read a book for a couple of weeks!

I'm with Mr Bungle on that and I think KiCad, Sprint etc is worth a thread in its own right.

Recently, two forum chums have got to grips with those programs and have each gifted me one of their first 'JLCPCB' PCBs based on PCBs I had an involvement in designing, but which needed converting to Gerber files (which I can't create) to have them made commercially. The PCBs cost just a pound or so and are works of art. Plated through holes, screen printed. I can attain a good standard of homebrew PCBs but they fall far short of JLCPCB ones and ironically probably cost me about a fiver for a 75mm square PCB and hours of work.

All for the sake of getting to grips with Sprint or KiCad.

JLCPCB aren't some little outfit down a back street. 800,000 customers in 170 countries and they turn out 20,000 PCBs a day. Quite why they want to bother with the likes of us is a mystery, but it's very much to our benefit that they do, at rock bottom prices and no minimum order value. Worth taking a tour of the factory:

https://jlcpcb.com/aboutUs

As many will know if they've followed and of my 'Homebrew' threads over the years, I've been an avid homebrew PCB maker (for more than 50 years in fact). In the early days, when Dalo pens came along, I gave them a go, but had little success with them. Try as I might, the coating always proved too thin and though the tracks came out electrically sound, they were pockmarked with holes as though they'd been got at by woodworm. If I tried to apply a second coat, all if did was to dissolve the first layer, so I resorted to using Humbrol modelling paint instead.

Then back when magazines were full of constructional articles, and Practical Wireless was both 'practical' and about 'wireless' and had an eclectic range of other electronic projects (before it morphed into a Ham Radio mag which is neither practical nor about wireless), Veroboard came into vogue in the mid 60s. I was never very keen on it, but made countless projects with it, some quite complex.

Then magazines started to featured projects using PCBs, for which they provided the artwork, and a PCB service. Initially, I used to get a photocopy of the PCB, tape it over a piece of laminate, drill through all the holes, remove the paper and 'join the dots' with Alfac dry-print rub-down transfers, which have ceased production in recent years.

One technique I've often used, including in recent years, is to design or convert PCB layouts so they can be created by using a layer of sticky-backed plastic ('Fablon'). I stick it onto the laminate, glue a copy of the artwork onto the Fablon with a Pritt stick, then cut around the lines with a scalpel and rule, peeling away the waste. It has the merit of leaving lots of copper on the PCB which speeds up etching time, obviates 'undercutting' of tracks and pads, makes it easier to drill the holes and looks neat.

I've attached some examples showing the original artwork, and my conversion to the scalpel process to show what I mean.

In the late '70s there was an article in PE on how to make a UV light box, which I built. Initially I used pre-sensitised UV laminate with limited success. Hard to get the exposure right and the developer concentration. Either under exposed, or over exposed in which case the lacquer was washed clean off the board. Also, I was left with little useless offcuts of laminate. I then resorted to self-spray UV lacquer which I used with a good success rate, and if it failed, I could just clean the lacquer off the laminate and re-spray. Then along came negative resist UV dry film, which I've embraced with a vengeance.

In the early days, like many I guess, for the UV mask I used photocopied acetates from copy shops (Pronta Print et al - do they still exists?). Nowadays I use microporous film. Every stage of homebrew PCBs has to be spot on or failure ensues, and the surest way to fail is to use CAD software which isn't meant for DIY use (Thin tracks, small pads etc). I've ironed out all the wrinkles at each stage but it's a tortuous process, often taking longer to make a PCB than it takes to build the finished project.

The bottom line is that if I'd spent a fraction of the time I've spent doing this, getting to grips with Sprint or KiCad instead, I'd have save countless hours, and not a little expense. I need to re-direct my efforts - how hard can it be?

Examples of PCBs using the 'Fablon' technique:

Pic 1: Small regulated PCB - original layout converted to 'Fablon'.
Pic 2: Signal generator PCB.
Pic 3: An example of a section of a (poorly designed) PCB layout converted.
Pic 4: Two amplified loop antenna PCB layouts from Gary Tempest designed 'Manhattan' layouts.
Pic 5: A 'Cirkit' HF amateur radio 15 Watt HF transmitting linear amplifier.

Apologies for broadening the thread out from Dalo pen replacements, but it outlines all the alternatives I've used due to my lack of success using Dalo pens.

I hope it's of interest.

Bazz4CQJ 2nd Mar 2021 10:05 pm

Re: Dalo Pen replacement
 
Quote:

Originally Posted by David G4EBT (Post 1346082)
I'm with Mr Bungle on that and I think KiCad, Sprint etc is worth a thread in its own right.

Apologies for broadening the thread out from Dalo pen replacements, but it outlines all the alternatives I've used due to my lack of success using Dalo pens.

Well yes, but you do already have a thread going on KiCad https://www.vintage-radio.net/forum/...t=kicad&page=2 ;);).

B


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