Pennsylvania A3 Switcher (Kozo)

[Kim]

The first order of business for the day was to drill the holes for the staybolts.

So, I marked up their positions and used my cool new(ish) optical center punch to mark the centers.  I got the optical center punch about a year ago and just haven’t had a good opportunity to use it, but it was pretty handy here.


I set the boiler up on the mill and drilled the first hole.


Then test fit one of the staybolts to make sure I was drilling the right size!  Luckily, I was.


And proceeded to drill the remaining five holes.  Not a fast process in copper.


Then flipped the boiler over and did the same thing to the other side.


Now I needed to deburr the holes so the solder would flow well.  My wife recently got me this cool Noga deburring tool and this was the PERFECT use for it. (I saw Blondihacks using this tool and thought "That's cool! That could come in handy sometime!" So asked my wife for one for Christmas!  ).


It allowed me to deburr the firebox side of the holes.  I was also able to deburr the inside edges of those holes too – remember, they go through the outer firebox sheet and the firebox sheet itself making twice as many holes to deburr, with half of the sides almost impossible to get to!  But with this fancy little tool, I could deburr them all!  It did take a while, but it worked very well!  I don’t know how I’d have done it otherwise.


Then it was time to do the solder prep.  Lot of prep work, as always.  It’s not easy to screw those staybolts together when they are covered with flux!  Kinda a messy proposition.
Kozo shows making a little metal shield to help protect the edge of the firebox and that seemed like a good idea.  In fact, it seemed like such a good idea I made four of them, one for each edge (Kozo only shows one on the edge closest to where  you’re working – probably enough, but this just seemed like a good precaution.)


As usual, it took a long time to get this monster up to temp, but once it did, the solder started flashing quickly, and I worked around all six staybolts.  And, as has become my habit for this boiler, I added a second round of flux and solder to the stay bolts and did it again.


Then I carefully used the pliers and gloves to unstack my hearth, flip the boiler over, and rebuild the hearth.  Then placed solder and solder rings on the stay bolts on that side, heated it up, and flashed the solder. Twice, as is my current habit.
I was having problems with the torch on the second side – it just didn’t give me as much flame and heat as before.  I kept turning it up, but nothing would change.  Turns out, I was running low on propane! Yikes!  But luckily, by being persistent, I was still able to get it up to temp and flash all six solder rings, even the second time.  But it took longer than it should have.  I think that’s why it looks like such a crispy critter here.


Because of my torch/fuel problem, and how it looked (so super black!) I was worried that I’d really messed up and ruined something.  But I waited for the boiler to cool and put it in the pickle.  Only time would tell...

After that, I went to the store and exchanged my propane tank for a full one!  There might have been a little bit left – enough to solder something small, with a small burner tip.  But there’s no way there was enough for the kinds of solder sessions I’ve been doing using those big burners!

OK, so once back from the store I pulled the boiler up out of the pickle and took a look.  While I couldn’t give the whole boiler a look over, I’m pleased to say that what I could see looked good




I’d had some hair-brained idea that I could solder both the outside and inside of the staybolts today.  But there was no way.  The insides will have to be soldered tomorrow.  I don’t know if that will be easier or harder…  I’m kinda thinking I’ll back off to the 32mm burner (one size down from where I was at today with the 35mm).  It makes just a tad smaller flame, and I think that may be good for inside the firebox.  It will likely hold the heat better than the outside area did.  In fact, it might hold the heat TOO well… guess we’ll see!

Thanks for following along,
Kim

[crueby]

Great job on the outside  bolts, hope that the  inside  goes as well! Does kozo show shields for the other joints on the inside as well?

[cnr6400]

 

[Prowler901]

Awesome!

[Kim]

Thanks Chris, Jeff, and Todd! 

Does kozo show shields for the other joints on the inside as well?

Hmm... I'll have to look at the book again to know for sure.  But now that I think about it, it seems like he may show the shield on the picture for soldering the inside of the staybolts, not the outside.  I'll have to double-check.

Kim

[crueby]

Now that you have a  fresh propane tank, you may want to revisit your regulator setting too. You may have opened it too much thinking it was the issue, when it was the tank being low?

[ddmckee54]

Were you able to get the chips from drilling through the inner walls of the firebox out of the inside of the boiler, or will they just have to stay there?

[Kim]

Now that you have a  fresh propane tank, you may want to revisit your regulator setting too. You may have opened it too much thinking it was the issue, when it was the tank being low?

Oh!  Very good point!  I'll have to back off the regulator for sure!  That could cause problems!    
Thanks for mentioning that!

Chris, have you noticed the torch acting differently as the tank gets close to empty?

Kim

[Kim]

Were you able to get the chips from drilling through the inner walls of the firebox out of the inside of the boiler, or will they just have to stay there?

Yes, I was able to dump the chips out the front of the boiler since the front tube sheet isn't in place yet.

And after all my deburring rattled the boiler around and blew air through all the holes till I didn't get any more chips out and heard no more rattling.  So I think I got it pretty well emptied of chips.   

Kim

[crueby]

Now that you have a  fresh propane tank, you may want to revisit your regulator setting too. You may have opened it too much thinking it was the issue, when it was the tank being low?

Oh!  Very good point!  I'll have to back off the regulator for sure!  That could cause problems!    
Thanks for mentioning that!

Chris, have you noticed the torch acting differently as the tank gets close to empty?

Kim

Yes, like you saw, the flame size decreases, less heat produced. I had same thing once, ran out in the middle of a session, learned to heft the tank before starting to make sure it was not getting low. You can look up the weight of the empty tanks online and weigh it to get a better idea of how much you have left. You'll never use all of whats in the tank.

[Kim]

Thanks Chris!
Good to know I'm not the only one who sees this.

Thanks!
Kim

[Kim]

To do the backside of the staybolts, I started by taking the staybolt nuts off.  It was a bit of a struggle, but I got there.  I ended up using those pointy vise-grips to get a few of them started.  And that actually worked pretty well and I didn’t mess any of them up too badly.   But removing them allowed me to get flux under the nut, so it was well worth the effort.



I ended up using the vice-grips for re-assembly too, fluxing the nuts as I went and placing rings of solder around each staybolt nut. I then set it up on the hearth.


Here’s a close-up of the inside of the firebox.  You can see I also put a small circle of flux on top of the threads.  I want to make sure the threads get silver solder in them too!   Also, note that I crammed some rock wool inside the firetubes and down in the crown of the firebox.  The goal of this was to prevent the top of the firebox from getting so much direct flame.  That is one of the things that caused me problems earlier if you recall.  I also used extra-easy grade solder for these joints to help prevent over-heating of the rest of the completed joints.


One thing I tried differently this time is to do some of the early heating across the whole boiler.   I don’t want to get it all silver solder hot, but I the whole unit needs to get a LOT warmer before I will be able to get my target area hot enough to melt silver solder.  And I don't want to have to add ALL of the heat through the area with flux on it!  Especially when I’m blasting the flame right on the flux, as opposed to applying it from the back side, which is my preference, when possible.  When you have to blast the flame right on the fluxed area it seems to boil the flux away much faster (even the black flux) so that it’s gone by the time the unit gets up to temp.   Anyway, after a while, I put the bricks back over the top and moved to just applying heat via the firebox area.


After a bit, I got it all up to temp and flashed all the solder.  Again, I did a second round of solder.  It was so hot in there I had to wear gloves to apply the flux-dipped solder with the tweezers.  The staybolts are pretty deep in the firebox too.  But I got it done and flashed the second round of solder.

With that side done I used gloves and channellocks as tongs to re-arrange the firebricks and flip the boiler over so I could do the opposite side.  Same drill as above – apply flux-dipped solder and flash.  Then do it again. Here’s the final result:


I did want to share this with you all – I should probably put it in the “stupid moves” sub-forum, but here it is anyway.  Yesterday after doing one of my second applications of flux-dipped solder, I apparently forgot to move the flux back to a safe place and left it WAY too close to the action.  You can see the result.  Luckily, I can still get the lid on but I don’t think it seals very well.  So as of yesterday, I’m keeping my Harris Black  Stay-silv flux in a ziplock bag to help keep it from drying out. 


Anyway, after letting the part cool I put it in the pickle.

Hopefully, we’ll get good news later!

Thanks for looking,
Kim

[crueby]

Quite an operation,  hopefully it  sealed well all round!

[cnr6400]

 

I do miss tins that used to be used to package things like flux. Much more practical for hot work areas than plastics. My personal favourite is resting a piece I've just welded on the first convenient thing, that piece if sheetmetal on - something- oh yeah! that's the garbage pail, now melting under the sheetmetal !    I've probably melted as much plastic in the shop with silly incidents as my local injection moulder!

Fingers crossed on the inner firebox soldering op! The pickle bath knows all, tells all. 

[Kim]

Thanks Chris and Jeff!

And here are the results from the pickle judge:

All six of the staybolt nuts look well covered on this side – at least from what I can see – visibility for the far side isn’t that great.


And the other side looks pretty good two.  The back staybolt nut on the left still has a bit of unmelted solder on it.  That’s a little messy, but it still looks like it has an adequate fillet all around.  There's a bizarre spot in front of the front right staybolt.  This looks to be where I may have drug the pointy stick through the solder as it was solidifying and it just left a nice flat like that.  Or something... I don't know for sure.  But it's solder, not a hole or anything.


So, all in all, not bad.  Doesn’t look like I ruined anything else yet.  At least, not obviously anyway

Tomorrow will be the front tube sheet, which is the last step before hydro-testing!
Kim