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Steve Laifman < One first kiss, >
B9472289 < one first love, and >
< one first win, is all >
< you get in this life. >
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Message-ID: <369A2192.256E32CC@flash.net>
Date: Mon, 11 Jan 1999 08:06:44 -0800
From: Steve Laifman <laifman@flash.net>
Reply-To: laifman@flash.net
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To: pete_stanisavljevich@sunserv1.valpak.com
Subject: Re: Sand Blast Stripping Headers
References: <199901100446.PAA21960@fep7.mail.ozemail.net>
<3699566F.C63672EC@flash.net> <3699FF9D.5FDE5521@mailhost.valpak.com>
Pete wrote me about my caution on sand blasting, and asked for a
recommendation of his headers. I thought that the answer might be
of sufficient interest to warrant distribution to the list. If you
aren't interested, delete now, as I do get rather detailed into
options.
Pete Stanisavljevich wrote:
> Steve,
>
> Does this warning apply only to sheet metal? I'm ready to have my
> exhaust manifolds sandblasted. I wonder if I should now.
>
> Thanks
>
> Peter S.
Pete,
I presume you have a rust coating on your headers, requiring
removal. If it's INSIDE, it's a tough job without liquids, and
there are crevices in the collector joints to retain fluids, but I
believe these can be sufficiently flushed and neutralized to
eliminate that both inside and out.
If you want a mechanical method, "sand-blasting" with walnut shells,
plastic beads, glass beads, etc. can do the job without damaging the
metal. These are, however, slower and finer means of removing
material. AS an example, for paint, many passes are necessary to
get the paint off, but the results are a very smooth, undamaged
surface and material. Takes off about 1 layer of paint/pass. Sand
blasters use 'bead blasting', but charge by the hour. The material
may be a little more expensive than sand, as well.
Since I don't know your contamination, it's hard to be definitive.
The 'sand-blaster shop', if they are a good shop, can tell you what
the best alternate material would be for your problem, other than
sand.
The heating and cooling of the exhaust system probably accelerates
the cracking of work hardened sheet metal more than anything on the
body, as the stresses are higher, and the temperature is a lot
higher. These both contribute to failure. Heck, these things fail
fairly early (compared to cast iron) anyway)
Keeping them looking good in the future, with cleaned or new
headers, is a good result of the Jett-Hot process of cero-metallic
flame coating of the inside and outside of the headers. Look
fantastic, in color, chrome-like, or ‘cast-iron’ look. Cost about
$300/set, so I'd start with new headers AFTER they have been bent
and dinged to fit. There are less expensive aircraft processes that
cost about 1/2 and are probably adequate. Jett-Hot has built a
reputation based on being the very best, and even header
manufacturer's (Hooker) say that the process is better than the one
they use on their best product. It's all money. I've seen Cobras
with $150 jobs on external pipes that you'd swear were chrome, and
seem to last years of racing.
Hope this helps.
Steve
--
Steve Laifman < One first kiss, >
B9472289 < one first love, and >
< one first win, is all >
< you get in this life. >
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