Why is my gold not very good

[STAINER88]

Hi I am trying to gold plate some aluminium, Ive got up to the gold plating stages but thats were the problem starts,.
when I am finished the gold it looks nice but when I hold it under a light it looks very patchy.
I think it may have something to do with the polishing stages I am doing it by hand but I have noticed that when I am finished I have removed some gold.
What I am trying to get is a rich bright looking gold using the plug n plate method can anyone give me some advice on what I am doing wrong and how would I acheive my desired result,
Many Thanks
Davie

[lcaswell]

Please detail all your steps from bare aluminum to gold plate and describe your parts in more detail.

[STAINER88]

Firstly I polish the part to required shine
I then leave it in Caswell SP deox n desmut for half a hour
Rinse
I put it in Caswell Zincate untill I get a even grey coating
Rinse
into Caswell EN for 30 min
Rinse
Polish to higest shine I can get
Brush copper plate
rinse
Brush nickel plate
rinse
Brush gold plate
rinse and polish by hand

It all goes well upto the pre gold stage I am able to get a nicew shiney nickel plate but when I gold plate it looks nice untill I move it under a light and its very patchy and darker in some spots.

I have tryed re-copper,Nickel and gold but when I was polishing I noticed I took alot of the gold off even altough I am polishing by hand.

The bits that have turned out ok have a nice thick gold look to them but I am stuggling to get a even coverage

Any suggestions would be gratfully recived

[STAINER88]

Juts thought id let everyone know Ive solved that problem with help from caswell tech support.
I havent been doing the prep work right and also doing to many stages.
Problem is know I cant activate the EN to gold plate it and its been left with a blurry black mark on what was a very bright mirror shine on the nickel
how do I activate it ive tryed activator and SS activator but nothings worked

[CarWiz]

Hi Davie, Got your message. I'm not experienced in the brush plating so I can't help you a lot there. It sounds like you got your answers from tech-support already on the steps. I hope they told you to go from the EN to gold. A possible polish and clean before gold plating may be necessary.

It sounds to me like you might be getting some zinc contamination. That could be from too long in the zincate solution and a contaminated EN tank. The dip should only be for about 5-10 seconds if you're getting a good reaction (fizz). After that, remove and let the item dry. From there, go to the EN plating then rinse. It should be ready to gold plate at this point but you may get some dry ring spotting if the item comes out of the hot EN tank and starts to dry before you hit the rinse. If this happens, you can polish and clean before going to the gold.

The most important part of plating is getting and keeping the item clean. After a polish and clean, do the water break test. It must pass this test before any further steps. And once you pass this test, the item should not be handled. Use hangers or plastic tongs but do not touch the item with your bare hands, rubber or latex gloves. Use only 100% nitrile gloves. And be careful of what you touch when wearing these. It's easy to cross-contaminate if you handle other objects then go back to your plating. Treat your gloved hands like the item and rinse often.

Some folks have gotten away with tap-water rinses. There's too many variables in tap water and it varies by city. Stick with distilled water for all your chemicals and rinses. This alone eliminates many problems.

Ken

[STAINER88]

Ken Thanks for the suggestions. I am thinking that mabey there is a protective layer from the polish I used. I looked at the part last night and there is a layer of something that has crystalised over it. I degreased the part and then e-cleaned it but I cant think what possible has happend except mabey that.
The part was deffo clean before I tryed to gold plate its the only thing i can think of.
The polish I used was best aluminium polish very expensive stuff and it does say protects on it so mabey I just havent got the protective layer off although I put alot of work into the pre prep stages.
I have succesfully done this a few times but the gold has never been great just ok but I have never polished the nickel to such a high shine before so I will give it a bash tonite and ill come back here and report my findings.
Many thanks
Davie

[STAINER88]

Ive tryed again to gold plate my EN & still I am having no luck.
I tryed degreasing in MEK then good wash but it still wont activate
has anyone ever had problems activating electroless nickel and if so how did you get round it.