GDII's 1990 G-Limited

[GDII]

The first attempt not going so well, I stripped the zinc off to try again

[GDII]

Attempt number 2 was much better. I put the bath in the sun to heat it to 24c and tried again. Still no brightener in the bath, just zinc. Results were sooo much better. The dark spots are water on the part still drying. The rough surface is pitting from the rust.

IMG_20220926_213106.jpg (489.38 KiB) Viewed 392 times

[GDII]

Attempt number 2 with the bolts. Much better too.

IMG_20220926_192036.jpg (295 KiB) Viewed 392 times

IMG_20220926_192046.jpg (273.68 KiB) Viewed 392 times

[GDII]

You can see the difference between the right bolt with the warmer bath and the left bolt with the cold bath. Quite a bit nicer.

IMG_20220926_211851.jpg (166.67 KiB) Viewed 392 times

[GDII]

Next step was to finish up mixing all the chemicals to complete the system.

This is gold passivate. You mix 15ml per 985ml of distilled water. This makes the part change colour but also strengthens the zinc plating to be more durable. You first plate the part in the bath, wash it off, use an activator acid solution and then dip it in the passivate. More on this later.

IMG_20220927_200916.jpg (331.25 KiB) Viewed 392 times

IMG_20220927_201133.jpg (301.07 KiB) Viewed 392 times

IMG_20220927_201151.jpg (235 KiB) Viewed 392 times

IMG_20220927_201222.jpg (385.99 KiB) Viewed 392 times

[GDII]

This is the blue/silver dip. It helps strengthen the zinc plating without significant colour change.

IMG_20220927_201419.jpg (404.37 KiB) Viewed 392 times

[GDII]

Mixing up the Metex IT acid dip for passivating. You use this to make the passivate hold onto the zinc surface better.

IMG_20220927_202059.jpg (390.69 KiB) Viewed 392 times

IMG_20220927_202103.jpg (326.07 KiB) Viewed 392 times

IMG_20220927_202423.jpg (545.43 KiB) Viewed 392 times

IMG_20220927_202747.jpg (259.99 KiB) Viewed 392 times

[GDII]

Last but definitely not least is the TMA brightener. This makes the zinc plating shiny in the bath. Initially I didn't want to add it until I had seen how it came out without it. But it makes sense to use it now to make things shiny.

[GDII]

To assist in making the bath sit at the correct temperature of 25-30c I purchased a fish tank heater. It can be set to approximately the right temperature so it should be suitable for this. You might also see a fish tank pump. This keeps the bath circulating to prevent large bubble build up on the part and bursting leaving marks on it. It also helps the solution move around evenly distributing the zinc on complex shaped parts.

[GDII]

Let's try this again. This bracket will be used on the engine. It is the support for the CT15B turbo to the 3SGTE block. Stripped back to bare steel.

After going through the parts wash for a final clean and 2 water rinse baths it will go into the plating bath for 45-60mins at approximately 0.5-0.7amps. Hanging it on the negative bar.

Set the part in the bath for 45-60mins and twiddle my thumbs waiting. I tweaked the amps until I saw a small amount of bubbles coming off the part. Too much current and you burn the part. Leaving black spots or patches on it.

The last bit of the process lined up ready for the plated part.

RB3: Distilled water bath 3 for rinsing off the zinc electrolyte.
Metex IT:To prep the part for the gold chromate.
RB4:To wash off the Metex IT.
Gold:To make it, Gooooolddd...
RB5:Final dip bath. You dip it in and take it straight out. No swishing around.

This is now plated. The shiny bits were smooth without rust attacking them but the pitting makes it look a bit dull. It's protected now. I'm rather impressed with the brightener changing how the zinc looks on the part vs just zinc.

IMG_20220927_220930.jpg (361.83 KiB) Viewed 392 times

Rinse bath 3, Metex IT for 30 seconds, rinse bath 4 and.....

IMG_20220927_220939.jpg (366.08 KiB) Viewed 392 times

IMG_20220927_220953.jpg (465.14 KiB) Viewed 392 times

[GDII]

Out of the gold chromate! 30 seconds in there is plenty long enough. What a difference!

And final results! I'm quite impressed with this as my first go. I'm still letting it dry over at least 4 days to fully harden.

IMG_20220927_221207.jpg (309.71 KiB) Viewed 392 times

IMG_20220927_221632.jpg (317.49 KiB) Viewed 392 times

IMG_20220927_221640.jpg (375.92 KiB) Viewed 392 times

IMG_20220927_221643.jpg (322.55 KiB) Viewed 392 times

[GDII]

Plating test number 3! First off I had to strip the rust from the nuts and bolts. I decided to use CRC Evaporust to do the job safely. It definitely works well, just takes a bit of time but well worth the wait. This doesn't attack good steel or zinc so it's safe to use, even standard white vinegar will remove the zinc. It does seem to go after the gold colour of the zinc so not fully resistant to it.

[GDII]

All the rust is gone so time for a wash and then dropping them in the acid bath to remove the zinc. Fizzy!

[GDII]

Following the same process as before, this is straight out of the plating bath. Next step is chromate.

IMG_20220929_214525.jpg (334.74 KiB) Viewed 401 times

IMG_20220929_214530.jpg (298.16 KiB) Viewed 401 times

After the blue/silver passivate they are looking so much better than they did 2 days ago covers in rust and dull zinc.

IMG_20220929_214924.jpg (346.22 KiB) Viewed 401 times

IMG_20220929_215232.jpg (167.07 KiB) Viewed 401 times

[mknz]

This is so extra, but I like it