Caswell copy cad plating question...

[Greg L.]

Now that I have everything that I need I plan on trying my kit in the next few days. One of the things I want to do is my rad cap and fuel pump but before I start I see I may have a problem!

What would be the best way to replate the fuel pump as the cap is crimped to the aluminum housing? I was going to clean up the pump as best as I can and prepare the steel part for plating, then mask off the steel part and paint the aluminum part. Once the paint is dry I would remove the masking from the steel part and then plate it. Once the plating is done I would use thinner to remove the paint from the housing and I should be done. Does this sound like the way to do this kind of part or is there a better way?

The rad cap might be easier as I was thinking that I could just plate the whole thing as I don't thing the zinc will take to the brass rivets or am I wrong?

Any suggestions on this are greatly appreciated.

[John D.]

Re: Caswell copy cad plating question...

Greg, Brass rivet will definitely end up zincad. If you have a 63 radiator cap don't forget that it may have an aluminum big washer under it. The chemicals will destroy that for sure. Been there. Ruined a nice original 63 style cap many years ago by giving it to a plater. John Pirkle, Peter Lindahl and others restore the caps I believe.

[Gerard F.]

Re: Caswell copy cad plating question...

Greg,

I think I'd plate the bottom of the fuel pump first, prior to painting or refinishing the aluminum. Below is a picture of my fuel pump being plated.


Both the cleaning and plating process will ruin any finish on the aluminum if you did that first. To plate the bottom, I masked the aluminum with waterproof tape just above the crimped rim. I used a brake line and pipe plug, to plug the inlet and outlet holes in the bottom. You don't want any of the plating mix or cleaners inside the pump. I even used the brake line for the cathode connection.

After cleaning and prep, I supported the pumped so that the crimped rim was just under the surface, and careful not to get any mix into the crank end of the pump. See my jury rigged setup with another brake line and the copper cathode bar to support the pump in the tank.

When you are plating you need to tilt and move the pump slightly, and stir the mix occasionally to keep gas bubbles from forming on the bottom. The zinc won't plate where bubbles form.

Here's the pump just after the dichromate dip.

After you plate the bottom then you can mask the rim and refinish the top. I beadblasted mine to a natural finish rather then paint it.

Greg, this was probably the most complicated part I've plated. If you are just stating out, you might try some simpler parts or scrap metal first to get your
cleaning and plating methods/procedures down first. For plating to take, the part must be down to bare metal and superclean, shiny if you want a bright finish. It usually takes longer to prep then to plate. Also thoroughly read the manual on preparation and plating procedures. At first , it is a trial and error process to get the methods down.

I hope you got a lab power supply with your kit. The fuel pump has a pretty large area for the dingy adapter they supply with the standard kit.

On the radiator cap, I think the zinc will take on the brass rivets, even though the book doesn't say so. Maybe mask them with the wife's nail polish, or plan on brushing the plating off the rivets with a dremel wire brush. I haven't done a radiator cap, so I'm just guessing.

Hope this helps,

Jerry Fuccillo
#42179

[Gerard F.]

Here's the finished fuel pump

I think I redid the dichromate dip on the base about 3 times until I got it right. The top was beadblasted only and protected with Triflow (or WD40).

I think John has a good point about the radiator cap. You wouldn't want to ruin an original part on your first plating project. A lot of these parts do cleanup well with a fine wire brush or nylon wheel, maybe some Jasco metal etch.

Jerry Fuccillo

[Harold# 43147]

Re: Caswell copy cad plating question...

If you want to mask areas as not to plate them I use Liquid Mask Film (Bob Lively Model Aircraft Inc) you can buy this at Hobby suppliers on line I buy Qts for about $18.00 you can buy smaller Qty's.It is a brush on Latex let first coat dry then apply second coat let dry then use razor blade or exato knife to cut out area and peel away. You can use this with painting also which it was designed for.I do all types of decorate plating on Religious items Brass Bronze Nickel Copper and I will have different plate on the same object and this what I use to mask.This will give you the best line you can get tape can not even come close.I have used this with acid and alklyn plating baths with no problems.If you guys want a good Dichromate conversion formula here is one for yellow 10 O/Z Sodium Dichromate to 1 Gal. Tap water (No DI water)1/2 O/Z Suphuric Acid concentrated. You can use Batt Acid at 1-1/2 OZ-Gal.You can find the Sodium Dichromate on Ebay. Hope this helps

[Greg L.]

Re: Caswell copy cad plating question...

Thanks guys. I did pick up a 3A power supply off of ebay so I should be okay in that regard. I'll also try and get some liquid mask film if it is avialable in Canada. If not, I'll check the hobby shops for an alternative or some water proof tape.

I don't really have any simple parts left as I sent them off the the plater when I had my backing plates redone. All I really have left is vacuum advances, condensers, fuel pumps a rad cap horn relay and other like components. I know the parts have to be spic & span or the plating won't take and that the final finish is only as good as the care taken during prep. Cleaning a single piece is easy, I just degrease and then scrub with a small stainless brush with diluted muriatic acid and it comes out just beautiful. But Jerry how did you clean the fuel pump assy without damaging the aluminum or the internals? I don't want to try my method on the pump as I'm sure it will ruin the aluminum housing.

[Harold# 43147]

Re: Caswell copy cad plating question...

Muriatic(33%Hydrochloric) acid & sulphuric Acid Ok on Alu.A good wire brush job on the Alu will give it that fresh cast look and you can seal the hole thing will spray clear to keep oxidation from starting.

[Gerard F.]

Re: Caswell copy cad plating question...

Greg,

I do a quick dip in dilute muriatic acid (3 to 1) and then brush it with a nylon wheel brush (Nyalok). A fine stainless steel brush would be OK too. Always neutralize with a Baking Soda solution, after an acid dip and spray it off with distilled water. Then degrease with the SP degreaser (it also neutralizes) and spray off with distilled water (see the Caswell test), before you put it in the plating tank.

If after plating and dipping in dichromate, the color is not right or spotty,
go through the muriatic dip, brushing, degreasing again, and then the redip in the dichromate again. It is trial and error. The dichromate dip is in the range of only 30 to 60 seconds to get the right color.

The shinier the part is before plating, the shinier it will plate. Don't be afraid to polish a part after plating and before the dichromate dip, just degrease it, and don't touch it with your fingers before the dip.

Plug all the holes in the fuel pump, don't get any of that stuff inside.
But try your method on a test piece first.

Jerry Fuccillo
#42179

[Greg L.]

Re: Caswell copy cad plating question...

Jerry,

I tried my kit yesterday and had 50-50 results.

I think my problem is with my power supply though. It is an 18v 3a variable one that I bought off of ebay but with the item being plated I can only get an output of .6 or so volts. It works great for very small items like capacitors, relays and of course nuts and bolts as these I would say turned out perfect.

Here is one of my capacitors. The lighting is poor so the pic is as well but I can say that it looks way better in real life! I used the liquid mask to protect the ends of it and this worked quite well.


I just turned up the current until it started to lightly foam and all was fine. They came out perfect with no buffing needed. However I tried to plated the piece of the wiper motor that the pump mounts to and it was much harder to do.

This is the piece.


As you can see it also turned out like new for the areas that are seen once the cover is installed. My power supply would not plate a piece this large without my help! To get this plated I had to hold it and rotate the perimeter for the entire operation so that a portion of it was just below the surface of the bath. I found that with too much of it in contact with the solution that I wasn't getting any bubbling action and it was turning quite dull. The PS was maxed at 3.4a and voltage was .6 and that was all she had... I could not increase the voltage to the 1-4 range that the book calls for. When I pulled it out I noticed that the voltage went up to 18+.... As I lowered it back in the voltage would decrease so I clued in that the surface area was too large and that he lower resistance was why my voltage was so lower. But with me holding and rotating the piece I could manage to have an output of about a volt or so and 1-3 amps depending on where I set the adjustment. This may sound confusing but I WAS controling the voltage output based on how much of the part was in contact with the bath...a very tiresome process! The end result was very nice but there is no way that I will be able to plate my fuel pump or vacuum actuators this way(I tried to plate the wiper motor armature housing and it had too much contact area with the bath even by using the same method as I did with the wiper plate).

I read and re-read the Caswell manual and it says 1amp/40sq" so I am WELL within that range. My 3amp power supply would barely plate my vacuum advance so I'm thinking that that is my limit.

What do you think is wrong here? Should I be able to run a piece at a higher voltage or is this how power supplys work? I have zero voltage control with an item this large in the bath...smaller items are no problem. What type/size of power supply do you have for your stuff? I see that your fuel pump was bubbling quite nice and even though I haven't tried mine yet I'm sure that my power supply will not be able to do that.

Any advice here from anyone is greatly appreciated as I am just starting out and so far am quite impressed with the results of the smallest items. I just think that I am doing something wrong as my 3amp power supply should be able to handle 120sq" based on Caswells manual but it seems to call it a day around 10sq" like my vacuum advance unit.

Thanks

Greg

[Jack H.]

Re: Caswell copy cad plating question...

You need a manual on operating your power supply... It should be self-regulating and most tell you to:

(1) Crank the current vernier up all the way, then increase the voltage vernier until you reach the desired output level.

(2) Leave the voltage vernier alone and reduce the current vernier to zero.

Now, go hook up the PS to your circuit and simply crank up the current to your desired max output level and IGNORE what the voltmeter reading indicates, it should be self-regulating at the level you last set...

[Greg L.]

Re: Caswell copy cad plating question...

Thanks Jack...I'll try that. The instructions are in a three page pocket sized manual so there isn't much in it but there is someting to the effect of what you just mentioned. I tried it as per the manual but I think I had the ciruit completed so I'll try it again before hand and I will ignore the voltage meter there after.

I'll cross my fingers when I plate a item larger than 10sq" next time.

Do you know if the 1 amp per 40 sq" is realistic or is Caswell just making it look good?

Thanks

Greg

[John M.]

Re: Caswell copy cad plating question...

Jack is exactly correct! The voltage is irrelevant. The only thing that makes a difference is current. Just regulate the current to get the desired level, and do not worry about the voltage.

I will tell you that I find Caswell's current reccomendations to be on the low side. I will plate as high as 1 amp per 15 sq/in. Usually the lower the current, the duller and more grey the finished surface. Generally speaking however, if you see bubbles comming off of the part being plated, the part will probably blister in a day or two. When it blsters, the area under the blister will be dark black. Agitation is the key to getting uniform results, and you can agitate the bath too much.

Regards, John McGraw

[Gerard F.]

Re: Caswell copy cad plating question...

Greg,

I used a Kikusui 0-8 volts, 0-5 amps on the fuel pump. A 0-18V with an output of 3 amps should do the job. However, the power supply sees the total resistance of the plating tank. Make sure you have good connections to the anode plate and the cathode bar. Also wondering if your power supply has adjustible voltaage or is it a straight 18 at no load.

Jack is correct, set your voltage first with zero amps. For zinc I usually set it at 4 volts at no load. Then with your part hanging in the tank on a copper wire to the cathode bar, adjust the amps up until you see a slight effervescence, then back off the amps slightly. Don't worry about amps and volts. Most times I'm reading about 1 to 1-1/4 volts during plating with the amps adjusted just below the effervescence level. Actually the lower the voltage, the better the plating but the longer it will take.

Also clean off your anode plate prior to each run. Dip it in muriatic acid, neutralize, then buff it with a fine wire wheel.

Remember practice makes perfect.

Jerry Fuccillo
#42179

[Harold# 43147]

Re: Caswell copy cad plating question...

Greg if you have a 3amp power supply you shound be able to plate a power booster if you have enough chemical. It sounds like you have a connection problem or your rectifier is bleeding A/C. I don't know what caswells electrolyte is (zinc chloride or zinc hydroxide)? Do they supply a brightner with there kit? You need to have some sort of circulating pump /filter to keep the bubbles from forming on part this will cause little pimples and you need to filter also as iron oxide will percipitate out form the steel parts if it is a chloride bath. Every thing has to be super clean to get good results.Slow the plating down will give much better results.You should have a small buffing wheel you can put on a bench grinder(Fannel Buff is Good) use a white compound and lightly buff the peices this will even up the brightness.

[Greg L.]

Re: Caswell copy cad plating question...

Thanks for all the helps guys. I'm quite anxious now to try my kit again but I'll have to wait until the weekend when I have some time.

FYI here is my power supply. How many square inches would you all think it should be able to plate?

http://cgi.ebay.com/Mastech-Variable-Linear-DC-Power-Supply-0-18V-0-3A_W0QQitemZ140036061588QQihZ004QQcategoryZ32720QQrdZ1QQcmdZViewItem

I think it will do the trick once I learn how to use it properly. I did try it with an open circuit and I have full voltage control from 0-18 and a bit so I hope it will work for me.

One thing that I am still a little unsure of is what the part should look like as it is being plated. The parts that I did manage to plate gave off very small bubbles that looked like foam and I think this is correct as these are the pieces that turned out the best. I would turn the amps up and it would foam like crazy and on a washer it almost looked like it got burnt. If I turned it down to the point that the bubbles just stopped, the piece would go a dull grey color and look terrible...so I would turn the amps back up a bit and the piece would turn out nice. I guess what I'm asking is should the piece be just bubbling a slight amount or should it just below this level with no visable bubbling? I found that slight to moderate bubbling would produce the best looking part with no buffing required to make it look new. But no bubbling action produced a part that was dull that even after buffing didn't really look all that great. I'm curious to see if my plating will last or if they will blister in a few days. I should also mention that I was slowly moving the piece in the tank to keep the bubbles away from the part because I don't as of yet have an agitator.

Does anyone have any ideas in how to make an agitator? There isn't really any room in the tank for the aquarium pump that Caswell supplys so I'll need another option.

Harold, as far what is in Caswell's solution, I really don't know. They do have a brightener though which I did use. Thanks for the liquid mask tip...that is great stuff!

Any other thoughts or ideas are appreciated.

Thanks again.

Greg
#45455