he worst humidity I've ever been in was in Missouri in August many years ago - but I don't think it was anywhere close to what you're talking about!

Nah, that's probably about the same as we get here.  I took a trip with the Boy Scouts to Philmont Scout Ranch in NM several years ago at the end of July.  Miserable here, and pretty much exactly the same in Memphis and Chicago.  Got to NM, got off the train and thought, wow this is nice!  Of course it was actually hotter and few days later I forgot to sunscreen my ears (doh!) and literally had blisters.

So yeah, we're pretty muggy, but at least we're not in danger of spontaneous combustion or anything.  Your 118 sounds a bit worse to me.

And to bring us back on topic, I solved the "cool my shop" problem by putting a small heat pump in.  It's a split unit, like a typical home would have, but the indoor part is completely self contained and hangs on the wall (no duct work, etc).  My shop is a detached garage, so I can't exactly mooch off the house (well, I guess I could have ran a duct across the driveway, but I don't think the wife would have appreciated that.   )

-j

Dude, is it raining inside?

No, but there is an evil looking black mold growing on the radiator in my office.

That's what you get in Alabama in the summer time, especially when you turn off HVAC at night and on weekends.  At the moment humidity is 18% worse in my office vs. outside (66% vs. a relatively low 48%).

-j

[inside the building]

I can't use it much now that the humidity is so high (right now it is 88 F and 49% humidity

 ;D

What I wouldn't give for 49% humidity.  It's 70% inside the building here.  Probably because the idiots shut down HVAC at night.

-j

If you're talking about sending out to a board house, my understanding is that holes for through-hole components are plated.  Your software (e.g. library components) probably specifies this for you.

-j

I don't think you can reliably expect solder to wick through an un-plated hole, and certainly not stick to an un-heated pad on the opposite side.

If the connection in question is a header (e.g. LCD connection), I have played games like solder the header upside down, such that the plastic spacer is well above the PCB and I can solder on both sides of the board.  After all pins are soldered on both sides, slide the plastic spacer down to the board (if there's room) or remove it entirely (but this can leave it a bit flimsy).

-j

I do not like the .032" I got from a surplus web site.  It flexes way too much, breaking solder joints, etc.  The copper is thin, too, but that's a separate issue.

I prefer .062" minimum.

Fiberglass (FR4, etc) is rough on tooling, but you're not cutting all that much when trimming a few PCBs (I'm assuming you're not going into business or making production level runs).  I use a cheap carbide tipped blade (same one I use for rough 2x4s, pressure treated lumber, etc).

-j

I got some stuff that was (IIRC) 0.032".  That's too thin for a shield, IMO.

The stuff you're talking about I don't think I would use for anything that required holes - maybe a small SMT-only board.

-j

Lazy Susan.

I have been using the plain old rosin

That's a flux, not a tin plating.

-j

Because 24VDC would require a transformer, rectifier, filters, and a regulator.  24VAC only requires a transformer.

-j

Typically the garden sprinkler solenoids are 24V AC, but they work just as well with DC.

huh?  You sure about that?

I haven't tries the solenoids, but I got a DC relay by mistake once and hooked it up to 24VAC - made a heckuva racket until I got the power killed.   Most definitely was not interchangeable...

-j

If you don't want to use relays, a solid state relay (SSR) would work, or at loads as low as this a discrete TRIAC would probably be the switching device of choice.  I'm pretty sure the sprinkler controller I've seen uses TO220 sized TRIACs for switching the AC side.  The conformal coating was such that I couldn't read any part numbers.

I googled a spec sheet that says 20 to 80 PSI pressure range, 0.3A inrush/0.2A hold current at 24VAC.  I would guess this to be pretty typical.

If you're operating with effectively no pressure (i.e. gravity flow) a simpler valve such as the refrigerator or washing machine type may be more appropriate, as I think these are direct acting rather than a diaphragm type like the sprinkler valves.  They'll typically operate on 120VAC; you'll switch them with an appropriately rated relay, SSR, or TRIAC.

The only windshield wiper systems I'm aware of (which is a very short list) are pumps, not solenoids, as they're simply pumping from a reservoir that's lower than the outlet.

-j

You can get sprinkler system solenoids at the local BORG (home center) that operate on 24VAC for about US$20 each, IIRC.  The 24VAC transformer should be nearby.

You'd have to switch AC current with the arduino, but that's doable, and in exchange you get a reasonably cheap and ready supply of valves.

-j

I think we may be talking about different kinds of shelving.

Yes, we are.  I'm talking about shelving like this mounted with clips like these.  The shelves themselves would be OK if they were lined and had a decent support system.

-j

It's not finding replacements (or even buying them, they're cheap), it's cleaning up the mess.  Last time it happened to me, it was exploding car-care products (polish, tire cleaner, etc etc) that made a huge stinkin' stainin' mess in the garage.

Environment doesn't seem to matter; those in the bedroom closets went first (climate controlled and dark no UV!).

You've probably got 8 or 10 years before it starts happening to you.

-j