Durafix, product review
captk...@webtv.net
I am sure several of you have seen the guys at the boat show weldiing
aluminum with a durafix rod and a propane torch. and wondered if this
stuff could be handy for "in the field" and remote repairs: (ie: where
there is no tig )
I bought a half pound at the miami boat show many years ago and have
experimented with the stuff only a few times.
The first time I had an opportunity to try a repair "in the field" was
during a busy time in the charter business. I had discovered a small
crack on our boarding ladder. Not a serious crack but my first
candidate for durfafix repair!
Our aluminum dive ladder was quite substaintial maybe 10' overall
length,
it was quite windy on deck and my first experiment was with my handy
portasol
( great tool but as it turned out not for this)
http://www.westmarine.com/webapp/commerce/command/ProductDisplay?prmenbr=201&prrfnbr=7803&outlet=
butane torch using the blowtorch tip. I just could not get the ladder
hot enough to make the durfix _flow_. Like they say on Home Improvement
"I needed more power" (ahrg ahrg ahrg !)
end day 1
I dug around in my shed and found a generic propane bottle type torch
nozzel, got a bottle of propane. And brought it to the boat The ladder
was large and cumbersome and I might have been more sucessfull if I
could have gotten the ladder out of the wind and into a sheltered
environment but even with the propane torch I was unable to create a fix
end day 2
After the sunset trip I was able to run to scottys hardware and get a
bottle of mapp (sp?) gas to experiment with . Even with Mapp gas I just
could not get the components hot enough in a windy open environment to
get the durafix rod to flow.
---> end experiment & took the ladder to a welding shop. :-(
******
The next experiment:
The job was replacing an engine bed n a 32 luhrs : to pull the port
engine of a 32 luhrs required pulling the 200 gallon aluminum fuel tank
to access the stb engine mounts of the port engine.
after draining the diesel and pulling the tank I found severe pitting
on one corner of the tanks bottom -but no holes... Maybe durafix could
be used as filler??
no portasol this time, and in a _sheltered from the wind_ walkway, using
a borrowed propane torch (not the questionable tip fom my shed) I was
able to get the durafix to flow !
It filled the pitted area niceley & saved my client the hassel of
transporting the large tank to a welding shop.
That was early 1999 and the tank is still in service.
1999 ... I was taking mig & tig welding classes and learning about
welding aluminum, maybe my inexperience had foiled my first attempts
with the ladder, maybe I just was not _patient_ enough to get the ladder
hot enough and maybe I did not realize how fast the heat quickly
dissipated from the aluminum tubing being cooled by the wind in the
unsheltered environment.
which brings us to the year 2001.
Now I can weld.
I have a mig, a tig and an oxy-acetylene torch.
the aluminum transfer case on a neighbors Harleydavidson had broken two
of the mounting ears off. creating a need for a repair similar to the
one shown of the carb here:
I used the tig to re-attach the ears, unlike the carb shown which is
rather robust, the Harley transfer case flares from the thick aluminum
ears to a thinner aluminum body and required care not to distort or burn
through the thinner area. Once I had the ears tacked I tried to fill
(and grind and fill) with the tig to build up the flare from thin to
thick but each time I risked burning through the thin stuff and decided
to quit while I was ahead rather than risk distorting or damaging the
case
I wondered if the durafix might help build up the flare around the
ears, this time I was able to use my oxy-actetelyn and was able to get
it hot enough without risking burnthrough to get the durafix to flow
nicely !! :-)
yes _do_ brush your repair item with a stainless brush to remove
oxides, also clean the durafix of oxides as the oxides have a higher
melting temperature.
There were a couple of booths at the Dania Marine Flea market selling
the stuff and the guys at the booths demonstrate the stuff making it
look easy ! (hey thats their job!) take a carefull look next time you
see one of these demonstrations at the size of the propane torch tip
they are demonstrating with --I thought it looked a size or two larger
than the _"generic"_ propane torch I had first used in my ladder repair
attempts.
if you have tried durafix and had less than satisfactory results keep in
mind the demonstrators at the show may have used a larger propane
torch tip capable of heating a spot quicker than the generic propane
tip in your shed and they probably picked a (thin) material to
demostrate with (cherry picked repair)
so be patient it may take _several_ minutes to heat the workpiece enough
to get the durfix to flow.
but bottom line, _yes_ the stuff works and could be very handy should
you require a repair in some remote area should you be cruising.
but just don't buy some and toss it in your cruising spares _ experiment
with it_ !
Douglas King
How would you compare this stuff in strength to a proper TIG weld?
Fresh Breezes- Doug King
edgar cove
captk...@webtv.net writes
>******
>
>The next experiment:
>
>
> The job was replacing an engine bed n a 32 luhrs : to pull the port
>engine of a 32 luhrs required pulling the 200 gallon aluminum fuel tank
>to access the stb engine mounts of the port engine.
>
>after draining the diesel and pulling the tank I found severe pitting
>on one corner of the tanks bottom -but no holes... Maybe durafix could
>be used as filler??
You welded a fuel tank in the boat? Even after draining there will be
traces of fuel inside and diesel can vaporize at a hot spot. I reckon
you are lucky to be around to tell the tale.
--
edgar (remove nospam from return address for e-mail reply)
captk...@webtv.net
Re: Durafix, product review
(Douglas King)
>Thanks for a very informative post.
thanks, I try.
I realized after working on the transfer case that I could not recall
ever reading a discussion on this stuff and thought I would share my
(limited) experience..
>How would you compare this stuff in strength
>to a proper TIG weld?
I wanted the transfer case to look nice so I would fill and grind and
fill and grind in an effort to develop an eye pleasing taper or flare
from the thicker ears to the thinner shell of the transfer case. When
"finish" grinding the repaired areas (dremel with grinding wheel or
sanding drum) the _surface_ areas where I tig'd and the areas filled
with the durafix were nearly indistiguishable from both one another and
the parent metal, both in finshed look and for lack of a better word
"grindability"
as for further comparing the "welds"
when tig welding we typically melt the parent or base metal and add
filler to the molten pool of base metal and when we are done what you
have is a new solid object,
when working with the durafix type rod you heat the base metal until
the filler _rod flows_ when brought in contact with the heated base so
the _base_ metals never "meld" but are joined descripitively in more of
a "solder" fashion or one might also attempt to more loosely describe
it as using the liquidified durafix rod as a "glue" between the parent
metals as the parent metals themselves have never liquified and
resolidified.
liquifying the parent metal is the key difference
Do I think you shoud scrap your plans to take tig welding classes to
build that arch/davit combo just using durafix?
No,
But durafix type products DO effectively fill a _niche_ market by
offering yet another _option_ (other than the metalmend/marinetex/
2part-epoxy type options) for _DIY_ in the field repair capability
with EASILY TRANSPORTABLE components ie:
bring only the rod and torch/ss brush / file or grinder/
sandpaper/safety goggles etc --> TO the job ,
--vs--
bringing the _job_ TO a tig (or mig) and then paying a weldor or even
worse yet paying a weldor to bring a portable mig or tig to your job..
(or attempting an epoxy type repair)
captk...@webtv.net
(edgar cove)
>You welded a fuel tank in the boat?
No, The fuel tank had been removed from the boat and stored adjacent to
the canal
>Even afterdraining there will be traces of fuel
>inside and diesel can vaporize at a hot spot. I
>reckon you are lucky to be around to tell the
>tale.
Actually, the fuel tank in question is enormous and literally a "shoe
horn fit" . The owner had been considering cutting it in half and
making two smaller and more magangable tanks out of it. The decision on
what to do about the tank was put on the "back burner"so to speak as man
other repairs were needed to be completed before the tank could be
reinstalled.
As I recall it is 10 feet long, maybe 18" wide and 24" tall, (300
gal??)
you know how cans of worms are one thing leads to another and another,
I wound up doing lots more work to the Luhrs than first discussed and
while my first post doesn't reflect the timeline involved and makes it
sound like I pulled the tank, drained and started brazing with the
durafix rod, in actuality after I drained the tank , probably 6 or 8
weeks passed in the middle of our subtropical summer and it would not
surprise me if tank would cycle through daily temps of 100 ++ in our
direct summer sun. Diesel does evaporate (some), the tank was "dry"
as opposed to wet with fuel before my attempt ...
I was both apprehensive realizing there was a potentail of danger but
willing to give it a try.
many things in life are dangerous and calculated risks.
some we get away with
some we don't
you ask me "should I do it ?"
I answer _no_
you ask me "can I do it?"
I answer _ I have_
as for next time?
10
9
8
7
6
5
4
3
2
1
BOOM !
(well ya never know !)
Douglas King
>
>
>
>
> (edgar cove)
>
> >You welded a fuel tank in the boat?
>
>
> ........... after I drained the tank , probably 6 or 8
> weeks passed in the middle of our subtropical summer and it would not
> surprise me if tank would cycle through daily temps of 100 ++ in our
> direct summer sun. Diesel does evaporate (some), the tank was "dry"
> as opposed to wet with fuel before my attempt ...
>
> I was both apprehensive realizing there was a potentail of danger but
> willing to give it a try.
Umm, that's not quite the same thing as gas-freeing it, y'know. I assumed
you had done something along the lines of gas-freeing or inerting the tank.
8 weeks is a pretty long time to air it out, but still... I am surprised you
were willing to roll those dice. I wouldn't!
Fresh Breezes- Doug King
HLAviation
>you had done something along the lines of gas-freeing or inerting the tank.
>8 weeks is a pretty long time to air it out, but still... I am surprised you
>were willing to roll those dice. I wouldn't!
I guess you never watched someone light off the filler neck of a gas tank and
weld it with gasoline still in it.
edgar cove
Douglas King
> >you had done something along the lines of gas-freeing or inerting the tank.
> >8 weeks is a pretty long time to air it out, but still... I am surprised you
> >were willing to roll those dice. I wouldn't!
>
>
> I guess you never watched someone light off the filler neck of a gas tank and
> weld it with gasoline still in it.
What do you mean by "light off the filler neck"? Burning off the vapor by
casually holding a match to the tank cap, like you would a bottle of whiskey or
lighting a fart?
You're right, I never watched somebody do that. And I wouldn't watch, except with
binocs from a long distance away. There is a difference between inerting a tank
and courting an explosion. A subtle difference, apparently....
Fresh Breezes- Doug King