Today's Message Index:
----------------------
1. 09:49 AM - Re: Chromed Nose gear Leg? ()
2. 10:25 AM - Re: Chromed Nose gear Leg? (flyv35b)
3. 10:40 AM - Re: Chromed Nose gear Leg? ()
4. 12:07 PM - Re: Chromed Nose gear Leg? (FLYaDIVE@aol.com)
5. 01:18 PM - Re: Chromed Nose gear Leg? (flyv35b)
Message 1
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| Subject: | Re: Chromed Nose gear Leg? |
--> TeamGrumman-List message posted by: <315@cox.net>
Thanks for all the responses to my question on chroming the nose leg. I
talked to the chrome shop again and was told that they did not use nitric
acid but only a weak cleaning acid and only for a brief time. The leg was
first nickel plated then chromed with hexavalent chrome and both processes
were for a short duration. The plater thinks that there should be no
concern over embrittlement from his plating of this part.
Hopefully he knows what he is talking about.
----- Original Message -----
From: <FLYaDIVE@aol.com>
Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
> --> TeamGrumman-List message posted by: FLYaDIVE@aol.com
>
> In a message dated 9/24/03 10:57:55 AM Eastern Daylight Time, 315@cox.net
> writes:
>
> > Hi Gang,
> > There is a nose gear leg that has been chromed on a Tiger. Does anyone
> know
> > for sure if this is undesirable? I have heard that hydrogen
embrittlement
> > is a problem. The shop that chromed the strut said the hydrogen should
be
> > gone withing 3 days of the chroming and that they chrome a lot of gear
> > legs????
> >
> > Ned
> ==============================
> Ned:
>
> Hydrogen embrittlement is caused by the use of Nitric Acid during the
> cleaning steps of the plating process. There is ONLY two ways to PREVENT
hydrogen
> embrittlement.
>
> 1 - After processing the item must be BAKED at 600 F for 1 hour or 350 F
for
> 8 hours. As you can imagine this can be costly and can affect the
Rockwell,
> and Tensile strength of many materials.
>
> 2 - The easier method is just to eliminate the Nitric Acid cleaning step.
> The only problem this causes it the quality of the bond of the plating.
>
> Chrome Plating to be a good preventive coating against rust has two paths
it
> can go:
> 1 - A very thick coating usually in the range of .005 to .010" (5
thousands
> to 10 thousands) thick.
>
> 2 - The second which is much better and can be done much thinner .003 to
> .006" is know as Tri-Vailant Chrome. This is a bit more costly, because
it has
> three coating process Copper, Nickel and Chrome.
>
> Now, three problems that should be considered with Chrome are:
> 1 - Thickness - Remember you have to get this tube back into the bracket
> which is a tight fit.
>
> 2 - Chrome is BRITTLE and the nose gear flexes quite a bit. Chrome is not
> know for Elongation or Compression abilities.
>
> 3 - Painting - Will you be painting the gear? Chrome does not take paint
> well.
>
> What I would recommend is Electroless Nickel. Electroless means that it
does
> not use electrodes as Chrome does. Electrodes cause High & Low current
> density areas of planting. So thickness control can become an issue as in
item #1
> above.
>
> And here is how I would plate it with Electroless Nickel (EN)
> NO Nitric Acid
> LOW PHOS Electroless Nickel
> Double Strike - That is:- Start the planting process and let it plate for
> about 15 to 20 minutes. Remove the part and Start the process all over
again
> from the strike on. Let it plate for an additional 15 to 20 minutes.
This
> should yield a thickness of .002 to .004"
>
> Now, you have a very high corrosion resistant coating and if you wish to
> paint it Nickel will take paint much better than Chrome. Also the
elongation and
> compression of Nickel is better than that of Chrome.
>
> BUT! What is your best and easiest bet? Sand blast it followed by a Bead
> Blast of 220 or 320 grit and Paint it. The SMOOTHER a metal surface is
the
> harder it is for rust to get a foot hold.
>
> Hope all this helps?
>
> Barry
> "Chop'd Liver"
>
>
Message 2
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| Subject: | Re: Chromed Nose gear Leg? |
--> TeamGrumman-List message posted by: "flyv35b" <flyv35b@juno.com>
Whether you chrome or nickel plate it, most likely will be illegal if you
care about that.
Why not just stip it completely, glass bead blast it and then prime it with
Vari-prime or a good epoxy primer and paint it with Imron. Then if you want
to go further get a clear adhesive backed strip of leading edge tape to put
on the front surface only.
Cliff A&P/IA
----- Original Message -----
From: <315@cox.net>
Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
> --> TeamGrumman-List message posted by: <315@cox.net>
>
> Thanks for all the responses to my question on chroming the nose leg. I
> talked to the chrome shop again and was told that they did not use nitric
> acid but only a weak cleaning acid and only for a brief time. The leg was
> first nickel plated then chromed with hexavalent chrome and both
processes
> were for a short duration. The plater thinks that there should be no
> concern over embrittlement from his plating of this part.
>
> Hopefully he knows what he is talking about.
>
>
> ----- Original Message -----
> From: <FLYaDIVE@aol.com>
> To: <teamgrumman-list@matronics.com>
> Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
>
>
> > --> TeamGrumman-List message posted by: FLYaDIVE@aol.com
> >
> > In a message dated 9/24/03 10:57:55 AM Eastern Daylight Time,
315@cox.net
> > writes:
> >
> > > Hi Gang,
> > > There is a nose gear leg that has been chromed on a Tiger. Does
anyone
> > know
> > > for sure if this is undesirable? I have heard that hydrogen
> embrittlement
> > > is a problem. The shop that chromed the strut said the hydrogen
should
> be
> > > gone withing 3 days of the chroming and that they chrome a lot of
gear
> > > legs????
> > >
> > > Ned
> > ==============================
> > Ned:
> >
> > Hydrogen embrittlement is caused by the use of Nitric Acid during the
> > cleaning steps of the plating process. There is ONLY two ways to
PREVENT
> hydrogen
> > embrittlement.
> >
> > 1 - After processing the item must be BAKED at 600 F for 1 hour or 350 F
> for
> > 8 hours. As you can imagine this can be costly and can affect the
> Rockwell,
> > and Tensile strength of many materials.
> >
> > 2 - The easier method is just to eliminate the Nitric Acid cleaning
step.
> > The only problem this causes it the quality of the bond of the plating.
> >
> > Chrome Plating to be a good preventive coating against rust has two
paths
> it
> > can go:
> > 1 - A very thick coating usually in the range of .005 to .010" (5
> thousands
> > to 10 thousands) thick.
> >
> > 2 - The second which is much better and can be done much thinner .003 to
> > .006" is know as Tri-Vailant Chrome. This is a bit more costly, because
> it has
> > three coating process Copper, Nickel and Chrome.
> >
> > Now, three problems that should be considered with Chrome are:
> > 1 - Thickness - Remember you have to get this tube back into the bracket
> > which is a tight fit.
> >
> > 2 - Chrome is BRITTLE and the nose gear flexes quite a bit. Chrome is
not
> > know for Elongation or Compression abilities.
> >
> > 3 - Painting - Will you be painting the gear? Chrome does not take
paint
> > well.
> >
> > What I would recommend is Electroless Nickel. Electroless means that it
> does
> > not use electrodes as Chrome does. Electrodes cause High & Low current
> > density areas of planting. So thickness control can become an issue as
in
> item #1
> > above.
> >
> > And here is how I would plate it with Electroless Nickel (EN)
> > NO Nitric Acid
> > LOW PHOS Electroless Nickel
> > Double Strike - That is:- Start the planting process and let it plate
for
> > about 15 to 20 minutes. Remove the part and Start the process all over
> again
> > from the strike on. Let it plate for an additional 15 to 20 minutes.
> This
> > should yield a thickness of .002 to .004"
> >
> > Now, you have a very high corrosion resistant coating and if you wish to
> > paint it Nickel will take paint much better than Chrome. Also the
> elongation and
> > compression of Nickel is better than that of Chrome.
> >
> > BUT! What is your best and easiest bet? Sand blast it followed by a
Bead
> > Blast of 220 or 320 grit and Paint it. The SMOOTHER a metal surface is
> the
> > harder it is for rust to get a foot hold.
> >
> > Hope all this helps?
> >
> > Barry
> > "Chop'd Liver"
> >
> >
>
>
Message 3
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| Subject: | Re: Chromed Nose gear Leg? |
--> TeamGrumman-List message posted by: <315@cox.net>
Why would it be illegal?
----- Original Message -----
From: "flyv35b" <flyv35b@juno.com>
Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
> --> TeamGrumman-List message posted by: "flyv35b" <flyv35b@juno.com>
>
> Whether you chrome or nickel plate it, most likely will be illegal if you
> care about that.
>
> Why not just stip it completely, glass bead blast it and then prime it
with
> Vari-prime or a good epoxy primer and paint it with Imron. Then if you
want
> to go further get a clear adhesive backed strip of leading edge tape to
put
> on the front surface only.
>
> Cliff A&P/IA
> ----- Original Message -----
> From: <315@cox.net>
> To: <teamgrumman-list@matronics.com>
> Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
>
>
> > --> TeamGrumman-List message posted by: <315@cox.net>
> >
> > Thanks for all the responses to my question on chroming the nose leg. I
> > talked to the chrome shop again and was told that they did not use
nitric
> > acid but only a weak cleaning acid and only for a brief time. The leg
was
> > first nickel plated then chromed with hexavalent chrome and both
> processes
> > were for a short duration. The plater thinks that there should be no
> > concern over embrittlement from his plating of this part.
> >
> > Hopefully he knows what he is talking about.
> >
> >
> > ----- Original Message -----
> > From: <FLYaDIVE@aol.com>
> > To: <teamgrumman-list@matronics.com>
> > Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
> >
> >
> > > --> TeamGrumman-List message posted by: FLYaDIVE@aol.com
> > >
> > > In a message dated 9/24/03 10:57:55 AM Eastern Daylight Time,
> 315@cox.net
> > > writes:
> > >
> > > > Hi Gang,
> > > > There is a nose gear leg that has been chromed on a Tiger. Does
> anyone
> > > know
> > > > for sure if this is undesirable? I have heard that hydrogen
> > embrittlement
> > > > is a problem. The shop that chromed the strut said the hydrogen
> should
> > be
> > > > gone withing 3 days of the chroming and that they chrome a lot of
> gear
> > > > legs????
> > > >
> > > > Ned
> > > ==============================
> > > Ned:
> > >
> > > Hydrogen embrittlement is caused by the use of Nitric Acid during the
> > > cleaning steps of the plating process. There is ONLY two ways to
> PREVENT
> > hydrogen
> > > embrittlement.
> > >
> > > 1 - After processing the item must be BAKED at 600 F for 1 hour or 350
F
> > for
> > > 8 hours. As you can imagine this can be costly and can affect the
> > Rockwell,
> > > and Tensile strength of many materials.
> > >
> > > 2 - The easier method is just to eliminate the Nitric Acid cleaning
> step.
> > > The only problem this causes it the quality of the bond of the
plating.
> > >
> > > Chrome Plating to be a good preventive coating against rust has two
> paths
> > it
> > > can go:
> > > 1 - A very thick coating usually in the range of .005 to .010" (5
> > thousands
> > > to 10 thousands) thick.
> > >
> > > 2 - The second which is much better and can be done much thinner .003
to
> > > .006" is know as Tri-Vailant Chrome. This is a bit more costly,
because
> > it has
> > > three coating process Copper, Nickel and Chrome.
> > >
> > > Now, three problems that should be considered with Chrome are:
> > > 1 - Thickness - Remember you have to get this tube back into the
bracket
> > > which is a tight fit.
> > >
> > > 2 - Chrome is BRITTLE and the nose gear flexes quite a bit. Chrome is
> not
> > > know for Elongation or Compression abilities.
> > >
> > > 3 - Painting - Will you be painting the gear? Chrome does not take
> paint
> > > well.
> > >
> > > What I would recommend is Electroless Nickel. Electroless means that
it
> > does
> > > not use electrodes as Chrome does. Electrodes cause High & Low
current
> > > density areas of planting. So thickness control can become an issue
as
> in
> > item #1
> > > above.
> > >
> > > And here is how I would plate it with Electroless Nickel (EN)
> > > NO Nitric Acid
> > > LOW PHOS Electroless Nickel
> > > Double Strike - That is:- Start the planting process and let it plate
> for
> > > about 15 to 20 minutes. Remove the part and Start the process all
over
> > again
> > > from the strike on. Let it plate for an additional 15 to 20 minutes.
> > This
> > > should yield a thickness of .002 to .004"
> > >
> > > Now, you have a very high corrosion resistant coating and if you wish
to
> > > paint it Nickel will take paint much better than Chrome. Also the
> > elongation and
> > > compression of Nickel is better than that of Chrome.
> > >
> > > BUT! What is your best and easiest bet? Sand blast it followed by a
> Bead
> > > Blast of 220 or 320 grit and Paint it. The SMOOTHER a metal surface
is
> > the
> > > harder it is for rust to get a foot hold.
> > >
> > > Hope all this helps?
> > >
> > > Barry
> > > "Chop'd Liver"
> > >
> > >
> >
> >
>
>
Message 4
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| Subject: | Re: Chromed Nose gear Leg? |
--> TeamGrumman-List message posted by: FLYaDIVE@aol.com
In a message dated 9/26/03 12:49:55 PM Eastern Daylight Time, 315@cox.net
writes:
> --> TeamGrumman-List message posted by: <315@cox.net>
>
> Thanks for all the responses to my question on chroming the nose leg. I
talked to the chrome shop again and was told that they did not use nitric
acid but only a weak cleaning acid and only for a brief time. The leg was first
nickel plated then chromed with hexavalent chrome and both processes were
for a short duration. The plater thinks that there should be no concern over
embrittlement from his plating of this part.
>
> Hopefully he knows what he is talking about.
======================
Dear 315:
I'm sorry but I do not get a warm fuzzy feeling with the response you
received from the plating shop. And I would not work with the feeling that:-
"Hopefully he knows what he is talking about."
First - What is the "weak cleaning acid"?
Cleaning is normally done with a weak solution of Nitric Acid. It is not how
weak it is it is the chemical action that takes place to form hydrogen and
hydrogen embattlement.
Second - When you say "both processes were for a short duration." The nickel
is a short process only about 15 minutes tank time. BUT! The chrome has to
be in there for about an hour. You want a build up of .005" minimum. The
time does depend on the concentration of the chrome, the amperage they will use
and what other parts will be in the tank along with yours.
Did you take diameter measurements at a particular location so you know how
much chrome they are putting on? But I think this is all a moot point, since
you are talking as the job is already done.
Good luck with the project.
Barry
"Chop'd Liver"
Message 5
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| Subject: | Re: Chromed Nose gear Leg? |
--> TeamGrumman-List message posted by: "flyv35b" <flyv35b@juno.com>
My first response would be to suggest you call your local FSDO and ask them
if they feel it is ok to chrome plate your nose strut without any approval.
They are the final authority about whether it is legal or not, not me.
You are making a rather major process change to a part that was never
designed or built with that in mind. This could affect the structural
integrity (probably from a fatigue standpoint) of a major structural part.
I think most people involved with aircraft will say that hydrogen
embrittlement is real. As an example, the step on my Bonanza is chrome
plated but they stopped short of plating the critical weld area where the
step tubing attaches to the bracket that attaches it to the fuselage. That
area was just painted. After all it would have been easier and nicer
looking if they had plated the entire step weldment. I wonder why? Maybe
is just that chrome is brittle and with flexing over time it would crack and
then get moisture inside and corrode under the chrome. Who knows.
How are you going to defend your actions if your nose strut breaks off and
the FAA and your insurance company get involved, as they surely will.
Cliff A&P/IA
----- Original Message -----
From: <315@cox.net>
Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
> --> TeamGrumman-List message posted by: <315@cox.net>
>
> Why would it be illegal?
>
> ----- Original Message -----
> From: "flyv35b" <flyv35b@juno.com>
> To: <teamgrumman-list@matronics.com>
> Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
>
>
> > --> TeamGrumman-List message posted by: "flyv35b" <flyv35b@juno.com>
> >
> > Whether you chrome or nickel plate it, most likely will be illegal if
you
> > care about that.
> >
> > Why not just stip it completely, glass bead blast it and then prime it
> with
> > Vari-prime or a good epoxy primer and paint it with Imron. Then if you
> want
> > to go further get a clear adhesive backed strip of leading edge tape to
> put
> > on the front surface only.
> >
> > Cliff A&P/IA
> > ----- Original Message -----
> > From: <315@cox.net>
> > To: <teamgrumman-list@matronics.com>
> > Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
> >
> >
> > > --> TeamGrumman-List message posted by: <315@cox.net>
> > >
> > > Thanks for all the responses to my question on chroming the nose leg.
I
> > > talked to the chrome shop again and was told that they did not use
> nitric
> > > acid but only a weak cleaning acid and only for a brief time. The leg
> was
> > > first nickel plated then chromed with hexavalent chrome and both
> > processes
> > > were for a short duration. The plater thinks that there should be no
> > > concern over embrittlement from his plating of this part.
> > >
> > > Hopefully he knows what he is talking about.
> > >
> > >
> > > ----- Original Message -----
> > > From: <FLYaDIVE@aol.com>
> > > To: <teamgrumman-list@matronics.com>
> > > Subject: Re: TeamGrumman-List: Chromed Nose gear Leg?
> > >
> > >
> > > > --> TeamGrumman-List message posted by: FLYaDIVE@aol.com
> > > >
> > > > In a message dated 9/24/03 10:57:55 AM Eastern Daylight Time,
> > 315@cox.net
> > > > writes:
> > > >
> > > > > Hi Gang,
> > > > > There is a nose gear leg that has been chromed on a Tiger. Does
> > anyone
> > > > know
> > > > > for sure if this is undesirable? I have heard that hydrogen
> > > embrittlement
> > > > > is a problem. The shop that chromed the strut said the hydrogen
> > should
> > > be
> > > > > gone withing 3 days of the chroming and that they chrome a lot of
> > gear
> > > > > legs????
> > > > >
> > > > > Ned
> > > > ==============================
> > > > Ned:
> > > >
> > > > Hydrogen embrittlement is caused by the use of Nitric Acid during
the
> > > > cleaning steps of the plating process. There is ONLY two ways to
> > PREVENT
> > > hydrogen
> > > > embrittlement.
> > > >
> > > > 1 - After processing the item must be BAKED at 600 F for 1 hour or
350
> F
> > > for
> > > > 8 hours. As you can imagine this can be costly and can affect the
> > > Rockwell,
> > > > and Tensile strength of many materials.
> > > >
> > > > 2 - The easier method is just to eliminate the Nitric Acid cleaning
> > step.
> > > > The only problem this causes it the quality of the bond of the
> plating.
> > > >
> > > > Chrome Plating to be a good preventive coating against rust has two
> > paths
> > > it
> > > > can go:
> > > > 1 - A very thick coating usually in the range of .005 to .010" (5
> > > thousands
> > > > to 10 thousands) thick.
> > > >
> > > > 2 - The second which is much better and can be done much thinner
.003
> to
> > > > .006" is know as Tri-Vailant Chrome. This is a bit more costly,
> because
> > > it has
> > > > three coating process Copper, Nickel and Chrome.
> > > >
> > > > Now, three problems that should be considered with Chrome are:
> > > > 1 - Thickness - Remember you have to get this tube back into the
> bracket
> > > > which is a tight fit.
> > > >
> > > > 2 - Chrome is BRITTLE and the nose gear flexes quite a bit. Chrome
is
> > not
> > > > know for Elongation or Compression abilities.
> > > >
> > > > 3 - Painting - Will you be painting the gear? Chrome does not take
> > paint
> > > > well.
> > > >
> > > > What I would recommend is Electroless Nickel. Electroless means
that
> it
> > > does
> > > > not use electrodes as Chrome does. Electrodes cause High & Low
> current
> > > > density areas of planting. So thickness control can become an issue
> as
> > in
> > > item #1
> > > > above.
> > > >
> > > > And here is how I would plate it with Electroless Nickel (EN)
> > > > NO Nitric Acid
> > > > LOW PHOS Electroless Nickel
> > > > Double Strike - That is:- Start the planting process and let it
plate
> > for
> > > > about 15 to 20 minutes. Remove the part and Start the process all
> over
> > > again
> > > > from the strike on. Let it plate for an additional 15 to 20
minutes.
> > > This
> > > > should yield a thickness of .002 to .004"
> > > >
> > > > Now, you have a very high corrosion resistant coating and if you
wish
> to
> > > > paint it Nickel will take paint much better than Chrome. Also the
> > > elongation and
> > > > compression of Nickel is better than that of Chrome.
> > > >
> > > > BUT! What is your best and easiest bet? Sand blast it followed by
a
> > Bead
> > > > Blast of 220 or 320 grit and Paint it. The SMOOTHER a metal surface
> is
> > > the
> > > > harder it is for rust to get a foot hold.
> > > >
> > > > Hope all this helps?
> > > >
> > > > Barry
> > > > "Chop'd Liver"
> > > >
> > > >
> > >
> > >
> >
> >
>
>
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