I have also heard of potential problems with sandblasting bulkheads. I was
preparing to blast the BH but was told not to by someone who knows more than
I do about such matters.
Any thoughts to this out there?
Rich Williams
Series II 109 SW
----- Original Message -----
From: Todd Ondick <greylildogs@hotmail.com>
To: <lro@works.team.net>
Sent: Tuesday, April 10, 2001 3:24 PM
Subject: LRO: Galvanizing Bulkheads
>
> >
> >I know this question has been flogged to death, but how does one get a
> >bulkhead galvanized without having it distort? I vaguely remeber someone
> >saying to search for an outfit that would pre heat/soak the item before
> >dipping? Or do you just wrench it into place and bolt 'er in.
> >
>
>
> Don't do it!
>
> >From the info I've gathered, there is NOTHING that will prevent heat
related
> warping at some scale. Regardless of how carefully you heat and cool, all
> lengthy, flat spans of unsupported thin sheet metal will warp a bit (esp.
> the panel above tranny tunnel and rear portions of shelves).
>
> The critical thing is how it is handled out of the zinc bath until the
piece
> cools. The bulkhead is mostly made of spot welded pieces of thin steel
> sheet. If man-handled while still hot, the whole thing can bend. bolting
> channel iron across critical spans will help (you usually pay by the
pound)
> but other surfaces can still bend. I saw a galv. SI bulkhead at David
> Gage's shop that looked like it had been set down on the engine side a bit
> too hard. The bottom/front of all the shelves & inst. panel had curled
up
> and in... ouch.
>
> That said, to do it over again, I wouldn't galvanize my bulkhead. Too
many
> things can and do go wrong. Mine didn't warp too much, but it had a large
> amount of slag and drizzle to grind off (HUGE PIA and it still ain't
> straight). To get it slag free they have to "bump" the piece, while still
> hot, adding to to the inevitable warpage. It is also hard to get the
piece
> totally free of slag because of it's compound angles & difficulty in
> manipulation so every section can drain. The passivating solution after
> the zinc bath also has a large effect on slag and surface appearance and
all
> galvinizers do not use the same process (so ask). Maybe, If you had a
> spare bulkhead to fall back on, knew the right questions to ask, and had a
> good working relationship w/ the folks at the galvanizers (or went thru
> someone who did), It might be worth considering. maybe but probably not.
>
> cheers,
> -todd
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>
This archive was generated by hypermail 2b30 : Tue Apr 10 2001 - 19:59:14 EDT