HomeRoast Digest


Topic: RIP original Heat gun (18 msgs / 485 lines)
1) From: Vicki Smith
After about 120 roasts, my heat gun died. It came with a three year 
guarantee, so it has been sent to the Heat Gun Abuse Judgement Board to 
see if it only qualifies for repair or if it will be replaced. Whilst 
waiting, I bought a new one. I decided to go with the same Mastercraft 
model, but this year it only came as part of a kit with a case and 
various tools and cost me $54 Canadian.
These are the specs: Dual heat: high 475 C (887 F), low 250 C (482 
F)12.5A, 1500W
I immediately noticed that with the new gun, I could keep the nozzle 
further from the beans and still get the same roasting times. I assume 
that means that it loses some oomph as it ages. I wonder what the 
Mastercraft people (assuming they actually look at it) will think of all 
the chaff in my heat gun? an old pantyhose over the air intake might 
prevent that, I suppose.
When I bought the first gun, I really wasn't sure if I would like 
roasting in a bread machine, or even if it would work. Spending more on 
a heat gum seemed silly. Now, with a fair amount of experience, I'm 
still happy with the choice in guns I originally made. The high setting 
is enough to get the job done, the low low enough to keep the roast 
going whilst prolonging the time between 1st and 2nd (though moving the 
gun away from the beans also adds to this, so theoretically almost any 
setting would work for this).
This time I played with a few heat guns at various stores. I really did 
not want to go up in weight (my heat gun weighs less than 1.5 pounds). I 
also found I did not like some of the grips and/or the nozzle length on 
various other models.
I'm not sure if anyone is planning a heat gun purchase, but I thought 
I'd put in my two cents anyway.
Vicki

2) From: Brian Kamnetz
Interesting info. Thanks, Vicki.
Brian
On 7/22/07, Vicki Smith  wrote:
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3) From: raymanowen
Master makes a bench mounted heater - not their normal heat gun with the to=
p
hat adjustable plate. I thought about setting one up with a section of flex
hose, but after a little fivethought, it seemed that the flexible high-
temperature hose would probably act like an air brake to the laminar flow,
and lose a lot of the heat due to the turbulence.
As a CAT engineer told me once: "Ray, Prior Planning Prevents P_ Poor
Performance." Still in the Prior Planning stage, I thought it was
+,+,unsmart to do any ducting of the airflow after it's heated.
A Kirby blower with vacuum hose connected to the blower outlet port would
blow air anywhere I wanted, or a little Hoover tank type vac would work. Th=
e
Hoover tank type would actually work better, because you can easily couple
the hose to either end of the tank- vacuum or blow.
All I gotta do is cobble up a heat gun-type nose for the hose far end. I
know the vacuum hose was heavy for the kids but for HG coffee roasting, the
hose, heat section and 12ga power line would weigh practically nothing
compared to any heat gun you want to compare.
You Appreciate I had the Kirby, not the Hoover, then I saw a Glorious
People's Orange HG at Tool King for $9.99. Powerful and light, I thought it
had a lifetime warranty. There was excitement when I was still running it
(3rd roast) and the lifetime ingloriously expired.
I was thinking of stretching an old nylon stocking over the intake at the
back of the GPOHG. I figured it had to be eating some of the chaff. I had
the nylon at hand
I just didn't know what the excess chaff indicator looked like. Hand held
fireworks at EOL. $36 at a big box store for a Wagner HG with a stated Two
Year warranty. I had already taken the bait. I've installed the prophylacti=
c
sock on the Wagner. May be some dumb, not plumb dumb.
Cheers -RayO, aka Opa!
Got Grinder?
On 7/22/07, Brian Kamnetz  wrote:
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4) From: Brian Kamnetz
Ray,
I should probably find some nylon screening to put over the air intake of m=
y
Master Appliance  751b. I keep thinking the air goes right past the heating
element and any chaff would combust immediately, but maybe not. If you thin=
k
it is a good idea to strain out the chaff, I guess I'd better think it's a
good idea too.
Brian
On 7/22/07, raymanowen  wrote:
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5) From: raymanowen
The motor in the Master HG is completely different from the lesser HG's.
Like the PI, it's a line voltage series wound universal motor- pretty
powerful and doesn't need a ballast to reduce the voltage.
I think you're right- if chaff gets into the blower, it will get hung up on
the screen mesh at the end of the heater nose, causing undesired restrictio=
n
and temperature rise.
The nylon hose will just melt- I don't believe it will burn, but test first=
.
With a cold gun, pull a stocking over the nose. Open the louver and switch
on the power to low until the nose melts through the nylon toe. Switch to
cool and pull the toe hole back until it's just on the red painted motor/
blower body.
The rest of the nylon will be covering the blower inlet, the motor vents,
the controls and the HG handle. The controls should be easy to operate
through the nylon mesh.
Cheers -RayO, aka Opa!
On 7/22/07, Brian Kamnetz  wrote:
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-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Might=
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Wichita (ex- NYC Paramount) WurliTzer- 1976

6) From: Vicki Smith
I knock the chaff away as I roast, using a BBQ brush, but, over time, 
some still gets into the heat gun. If I add a nylon "sock", I'd still 
have to use the brush to knock the chaff off of it--not to keep the 
chaff out of the heat gun, nut to keep it from blocking the air intake. 
It was the melting issue that has, so far, kept me from adding a sock. I 
also wondered if the nylon mesh would impede air flow enough to increase 
the chance of it overheating.
The fan on mine failed. I have no idea if the chaff collection in the 
gun contributed to that or not. It probably makes sense to spend a 
minute or so shaking the chaff out of the (cool) gun each time before I 
roast. I don't know why it didn't occur to me that this also was an 
option, but I shook my new gun around a bit and some chaff did fall out 
of it, not much, but I had only roasted 1 time with it at that point.
The casing for my HG is held in place by four screws. It would also be 
no big deal to take it apart every few months and remove the chaff. I 
already make an unholy mess periodically taking my Rocky apart for a 
thorough cleaning. I could add cleaning the heat gun onto my to-do list.
Then again, I could just return the heat gun under warranty if and when 
it poops out. That seems wrong though, eh?
Vicki
raymanowen wrote:
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7) From: John Moody
You don't want chaff in the heat gun.  It slows the airflow resulting in
higher temps inside the gun.
I had taken the screen out of mine so that the chaff would blow right
through, but the higher airflow resulted in lowering the HG temp too much.
John

8) From: Vicki Smith
LOL, I think we all know we don't want chaff in the heat gun. We're 
talking technique ;).
What amazes me is that with my minimal efforts (which was nothing more 
than brushing it off the exterior of the HG as I roasted) at keeping it 
out, my cheapo gun ($34 CAD) went ~120 roasts before failing.
v
John Moody wrote:
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9) From: Vicki Smith
John, I sounded mean. I am pre-coffee. Please accept my apology.
My heat gun, and many others, does not have a removable screen. It has a 
solid case with molded vents for air intake. I would guess that each of 
us will have to come up with slightly different ways to either keep 
chaff from entering the gun or getting it out, once it has gotten in there.
v

10) From: Vicki Smith
Here I am writing to myself...
It just occurred to me that if I took an inexpensive permanent coffee 
filter (a fake swiss gold), I could do some judicious snipping and 
create a removable snap on screen for the heat gun. The stores open here 
in a few hours, hummmm....
v
Vicki Smith wrote:
  My heat gun, and many others, does not have a removable screen. It has a
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11) From: John Moody
The permanent coffee filters do not have a very high percent open area; they
would be rather restrictive. For a quick simple test, watch how much
"brighter" the glow of the heating element gets when a chaff filter is
installed, or dulls when it's pulled off. If it does not change much, you
are OK.
Just for grins, you may consider a super simple approach like putting some
kind of netting over the intake and holding it in place with a rubber band
or tape. Depending on your results, you can improve on it from there.  A
space between the netting and the HG case allows much more air to actually
flow through the netting.
BTW, I understood your LOL for what it was; I did not take it as mean.
I'm not sure if Harbor Freight ships to your location, but this HG looks
like the same mfg. for only $10; but is also the one that lasted 3 roasts
for Ray, fwiw.
www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber5776
John

12) From: Vicki Smith
It's similar looking, but not the same. Mine draws at 12.5 amps and the 
temps of the two settings are different. I don't know if that is why 
Ray's lasted 3 roasts and mine lasted 120 or so, but the lower heat 
setting on the one you linked to is 630 F, 200 more than mine, but is 
only 8.5 amps.
I'm still going to give the fake swiss gold a try-well at least I will 
try snipping and placing it. I was thinking that the filter part would 
be some distance from the vents so that air could come in from the 
sides. I'll let you know later today. I will not try it if I think the 
air flow will be impeded enough to bork the heat gun. Frankly, I can 
live with replacing my gun once a year or so if I am not paying a whole 
lot for it, and my gun does come with a 3 year warranty.
V
John Moody wrote:
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13) From: Dan Bollinger
All heatguns will fail eventually because the bare nichrome slowly oxides each 
time it is used. The higher the temp, the more oxidation. And, each time it is 
cooled oxide flakes off exposing new metal. As this happens the wire becomes 
thinner in diameter. As is does so its resistance increases and eventually it 
can no longer sustain the amperage draw and 'fuses' out. Dan

14) From: Vicki Smith
That's really interesting, Dan.  My heat gun was definitely tuned on and 
off a whole lot of times. It was, however, the fan, not the heating 
element, that blew on mine.
My husband and I are old time techies. We both built and rebuilt a whole 
passel of computers (note I am old enough to use the word passel). When 
we were setting up new computers for our friends and family, we would 
routinely upgrade the fans. Lousy fans were a fact of life back then, 
and spending an extra few bucks on a better fan was a cheap way to keep 
the machines from frying the motherboard. We also gifted folks with cans 
of compressed air, and showed everyone how to take off the case and 
clean up the innards of their machines.
I have a feeling that chaff is to heat guns as cat hair is to computers.
Vicki
Dan Bollinger wrote:
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15) From: Brian Kamnetz
Thanks for the info about the Master HG, Ray. And thanks for the suggestion
regarding fitting the chaff screening material.
Brian
On 7/23/07, raymanowen  wrote:
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16) From: raymanowen
I became so enamoured of roasting with the $9.99 heat gun that I roasted on
3 successive Saturdays, which ended the career of the GPOHG. A time span of
two weeks, not:
" It would also be no big deal to take it apart every few months and remove
the chaff."
Yes it would- you might have to use the screwdriver and more before you
reassemble it. Want some practice? I could send mine. I back flushed it with
a shop vac on the two roasts I completed...
Cheers -RayO, aka Opa!
On 7/23/07, Vicki Smith  wrote:
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-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Mighty
Wichita (ex- NYC Paramount) WurliTzer- 1976

17) From: Vicki Smith
When I wrote earlier about blowing cat hair out of my computer case, it 
occurred to me that I could use compressed air to blow chaff out of my 
HG. Hummmm...all in all, 120+ roasts out of my $34 gun beats 3 out of 
your $10 one, RayO.
  I should quit my bitchin' and mebbe start counting my lucky stars.
v
raymanowen wrote:
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18) From: raymanowen
"...counting my lucky stars."
That's OK, as long as they aren't Shooting Stars, originating in your HG.
Put a sock on it.
Electric toasters and furnaces use open Nichrome resistive heaters, and they
keep running.
Cheers -RayO, aka Opa!
On 7/23/07, Vicki Smith  wrote:
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-- 
Got Grinder?


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