Dave Richards AA7EE

October 21, 2015

How Do Lacquered Boards Stand Up Over Time?

A query I hear from time to time about using copper-plated boards for Manhattan construction is what they look like after a few months or years. “How do they age?” is the question. My first such project, the WBR, was housed in an enclosure made from double-sided PCB material, and I could see that the outer surface had developed a bit of oxidation; a certain patina, if you will. My later projects weren’t made from this double-sided PCB – just single-sided, so I was going to have to open them up to see how they’d fared. Comparing how they looked, and remembering how I’d applied the lacquer to each did help in coming to some conclusions.

First of all, this is how the outside of the WBR looked shortly after I finished building it just over 4 years ago. It was already showing a few early signs of oxidation. However, it did fit together very well, and made quite a handsome enclosure –

The WBR in July 2011

I made 2 mistakes with this enclosure. Firstly, although the initial cleaning of the boards was done with Scotch-Brite scouring pads, the final cleaning was with Tarn-X. I later found that copper boards cleaned with Tarn-X develop streaking and oxidation. The streaking on this WBR enclosure was not anywhere as near as bad as I have seen with other boards, but it is definitely there. You can see it on the side panel in the next shot. The other mistake was to spray the lacquer too lightly. I was cautious about spraying it too thickly and causing it too pool, so I erred in the other direction instead. This is what it looks like from the outside today. Not bad, but definitely aged. You can see the areas on top where my fingers press against the case when I pick it up –

The WBR today (Oct 2015)

Here are a few more.

Before (July 2011) –

The WBR today (Oct 2015)

and today (Oct 2015)  –

The WBR today (Oct 2015)

The WBR today (Oct 2015)

If I were making the WBR again today, I’d stay away from the Tarn-X, and apply slightly thicker coats of lacquer.

Next, I decided to open up The Rugster. It was a little direct conversion receiver I had made by teaming up a standard NE602-type DC receiver front end with NM0S’ Hi-Per-Mite filter, set for maximum gain, so as to provide both 50dB of gain and narrow filtering. I built it into an enclosure made of single-sided copper-clad board on a red laminate. It had a really cool and compact look –

The Rugster in July 2012

It still looks the same from the outside today, but I was curious to know what the interior looked like. This was what it looked like when freshly-built 3 years ago, in Aug 2012. The treatment of the VFO toroid was my first ever attempt at using a hot glue gun, by the way. I am more skilled at it now. This particular toroid looked a bit of a mess –

The Rugster today (Oct 2015)

The same view today (Oct 2015), looking remarkably good. You can see that I added a high-pass filter on the back panel set to block signals from the AM broadcast band –

The Rugster today (Oct 2015)

I do remember that I sprayed slightly thicker coats of lacquer than on the WBR, leaving each coat for about an hour before spraying the next coat. Here are some more “after” shots –

The Rugster today (Oct 2015)

In the next one, the brighter patch on the red front panel is a splash of morning sun, and not a discoloration of the laminate –

The Rugster today (Oct 2015)

The 3rd project to be given a second look was the VK3YE Micro 40 DSB transceiver, which I built 2 years ago, in Oct 2013. Back then, the innards looked like this –

The VK3YE Micro 40 DSB Transceiver in Oct 2013

A couple of days ago (Oct 2015), it looked like this –

The VK3YE Micro 40 DSB Transceiver today (Oct 2015)

The VK3YE Micro 40 DSB Transceiver today (Oct 2015)

I used to clean my boards with Scotch-Brite pads but now find that fine steel wool scouring pads work even better. Then, when they’re clean, I dry them with clean bathroom tissue, making sure to blow any loose fibers off afterwards. Then I spray the first coat of lacquer. To this day, I still don’t always judge it correctly, and end up with boards that don’t age too well, but IMO, it is best to spray until it is just beginning to pool, ever so slightly. At this point, the lacquer is quite thick, but will smooth out before it dries. An hour later, you can spray the second coat. I’ll leave it up to your judgement as to whether you apply a 3rd coat (I usually do). From my experience, this way works quite well. I’ll be interested to hear details of anyone else’s experience with lacquering.

In the next post, I’ll talk a little about the methods I use when constructing Manhattan boards.

16 Comments »

  1. Great – I love all your posts and videos, and I know 5w will make out there. Hope to chat someday, but in the meantime, I’m gonna look at my breadboard and hang my head in shame for a short time… 73 de ab3ru

    Comment by jon milliren — October 21, 2015 @ 9:18 pm | Reply

    • You’ve just reminded me Jon – I really need to get a breadboard to test out circuits. It’s been on my “must get” list for a long time!

      73 and – no shame!

      Dave

      Comment by AA7EE — October 21, 2015 @ 9:21 pm | Reply

  2. I like the looks of the aged WBR case. Could even be steampunk with a little exterior brass. If you want your radios to have that “real radio” look then consider using hammered silver or copper paint. I think there is a krinkle paint too, but I have not used it.

    Bob, N5JYW

    Comment by Robert L. Pendergast, N5JYW — October 21, 2015 @ 11:03 pm | Reply

  3. Dave,

    You might also consider cleaning with denatured alchohol as the last step before lacquering. It is a great solvent and dries stresk free. I usually use it just before I top coa
    t.

    Cliff – WA9YXG

    Comment by Cliff - WA9YXG — October 22, 2015 @ 7:40 pm | Reply

    • Thanks Cliff, that’s a great tip. I have rubbing alcohol here, and I believe that’s similar. Will give it a try next time

      73,
      Dave
      AA7EE

      Comment by AA7EE — October 22, 2015 @ 8:28 pm | Reply

  4. Dave, man, your immaculate creations always amaze me! They could be exhibits in a HF art museum. Some hams will be amazed when they find your old rigs at a hamfest in 2115. You should sign and date your rigs.

    Comment by Rob. N7REP ex KD7KAR — October 23, 2015 @ 5:27 am | Reply

    • You’re too kind Rob! I did have a small health scare a couple of days ago though. As I was lying on the bed, doubled up in pain, my thoughts were, if the very worst happened, how I could ensure that my cats and homebrew projects found good homes. Oh – and who I was going to leave my money to. That was it, really. The cats were at the very top of the list!

      73,

      Dave.

      Comment by AA7EE — October 23, 2015 @ 10:11 pm | Reply

      • Wow, sure glad you bounced back Dave. Time to set up a trust and trustee for the kitties! Maybe your immaculate rigs should go to MOMA. Or ARRL. You could make a nice picture book of your fabulous rig collection. But that might cause many of us less-fastidiuos builders to give up in dismay. I sure envy how you can get all those mepads to line up so perfectly. Mine always seem to eschew conformity, and look like inebriated bumper cars, some even falling upside down. I can imagine you listening to a Bach sonata, sipping a nice chardonnay whilst deftly placing those pads with surgical precision. Hats off to you, Dave! Live long and prosper.

        73
        Rob

        Comment by Rob. N7REP ex KD7KAR — October 24, 2015 @ 4:47 pm

  5. Inebriated bumper cars – I love that description Rob!

    Comment by AA7EE — October 25, 2015 @ 7:00 am | Reply

  6. Hello Dave,
    I really love your posts and your great photos! Thank you for your work!
    How do you cut your boards? They look so exact.

    72/73 de Peter DL1PJ

    Comment by Peter Johe — November 2, 2015 @ 10:10 pm | Reply

    • Thank you Peter! –

      I cut my boards by scoring them deeply on both sides with the sharp blade of a box cutter/craft knife, and then flexing the board along the score mark until it snaps. Then I smooth the edges with a file. This method works really well for me.

      73,

      Dave
      AA7EE

      Comment by AA7EE — November 2, 2015 @ 10:28 pm | Reply

  7. Dave,

    A follow-on to our recent PM exchange — although, as explained, I have been a long time fan.

    This subject occurred to me when I first saw your work on the WBR. Not realizing it was 4 years old, I marveled how nice the cabinet looked and it was sobering to see that yours aged like my efforts had done. (cf. my paean to Mr Carlson, the A/B curve tracer device at http://righthandofzod.blogspot.com/2015/11/for-mr-carlson.html)

    Your “post-mortem” on this brings forth some valuable tips and advice and, as always, we are grateful for the documentation of both your successes and “failures”. Personally, I appreciate the detailed photos. Once I am done with my preliminary effort on the Far Circuit edition of the WBR, your layout and efforts will be flagrantly purloined ~~ with much attribution, of course, and elan!

    Seven-Twos from an ardent fan,

    Bill, k6whp

    Comment by William Phinizy — December 4, 2015 @ 10:11 am | Reply

    • Thanks Bill! If I had known then what I know now, I would have applied slightly thicker coats of lacquer. That’s how home-brew goes though – every time we build something, we learn. During the course of this learning, we acquire a collection of imperfect specimens – each one of them imperfect in it’s own unique way! The other (correctable) mistake I made with my first WBR was to use a cheap LM386 from eBay. It must have been an out-of-spec reject, as there was a strange “burbling” noise underneath the usual hiss you’d expect from one of these chips employed with the usual 10uF capacitor between pins 1 and 8. One of these days, I plan to swap that ‘386 for a better specimen.

      Let me know how things go with your WBR. and best of luck!

      73 for now,

      Dave

      Comment by AA7EE — December 4, 2015 @ 10:20 am | Reply

  8. I’m not clear on whether you’re lacquering the actual circuit boards themselves as well as the cabinets. If so, what do you do about things like connectors, socketed components, and buttons? Mask them?

    Thanks for the posts. Your creations have inspired me to buy the materials for my first attempt at this type of construction.

    Comment by Cymerian Designs — December 22, 2015 @ 6:16 pm | Reply

    • I lacquer the boards before they are used to construct circuits on. If they are being used to make an enclosure, then I lacquer the copper surfaces after the enclosure has been built and all main holes drilled, but before fitting all the connectors and parts.

      Hope that helps,

      Dave
      AA7EE

      Comment by AA7EE — December 22, 2015 @ 6:26 pm | Reply

    • Cymerian,

      I can attest to Dave’s methodology and add one thing: the acknowledged method heretofore proposed by Chuck Adams, k7qo, was to use Tarn-X to clean the boards prior to clear coating or lacquering them. I had done so and noted that they aged and “browned” over time and started to not look like Dave’s WBR or other efforts. Chuck has since recanted on the Tarn-x (cf. his You Tube video series on the 1-Watter rigs and related) and recommended Scotch Brite and alcohol and then coating a la Dave’s methods. My boards/enclosures following that path and using Dave’s recommendations have produced “ageless” stuff.

      On another point, I built the WBR article from QST using the Far Circuit board and it was *very* disappointing. Firstly, there were a whole host of article errors and subsequent corrections by N6BYT that did not make sense. Secondly, the audio quality/level was abysmal — as in a faint whisper. (Nothing wrong with the Far board but I am rapidly falling out of love with QST projects as being flat out error-laden and unreliable. Their article editing is absolutely atrocious!)

      So, I am proceeding to mimic Dave’s effort here. Hell, there are several videos with proof of concept and, besides, it looks so much more handsome. Fundamental in this method is the use of the QRPme squares which I highly recommend. SO then there’s that.

      I am given to understand that Dave might be “de-energised” on this subject but it is a marvelous effort and I hope he can mentor us along to completion.

      I am very grateful for his leading the way!

      If you wish to conflabulate with me on your efforts, I am reachable at the ubiquitous call sign + arrl dot net address. Hope to hear from you!

      72/73,

      Bill, k6whp

      Comment by The War Planner — December 22, 2015 @ 6:54 pm | Reply


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