powder coating outdrive

[j_cizzo]

I have a volvo DP-A outdrive and it needs to be repainted so I was wondering about powder coating it. Apparently powdercoating is much more durable than paint, so I was going to have the whole thing powdercoated, otherwise I'd use etch prime with imron.

I've searched all over the web and emailed people have never gotten a response. so maybe someone here knows. can it be done? or will the heat from the oven alter the casting?

thanks

 

[Scaaty]

Re: powder coating outdrive

Something tells me rubber seals and an oven not a good idea..

 

[HT32BSX115]

Re: powder coating outdrive

You could probably do it, but to do it right you'd probably have to completely disassemble the drive so you could powdercoat the housing with nothing inside.....Then reassemble.

It probably wouldn't be worth it.

 

[Don S]

Re: powder coating outdrive

I have never heard of anything "below the water line" being power coated. It may not hold up as well as a good paint job.
What you need to do is clean the drive up, prime it and repaint it with some good paint. I've used RustOlem with great results on drives.
Then, make sure your bonding system and the sacrificial anodes are all working properly, and changed on time. Where you keep the boat may also have boats around it that can cause YOUR drive to get eat up. There are tests with a meter that can isloate the problem.

 

[wire2]

Re: powder coating outdrive

Powder coat is merely polyester powder. When fused in an oven on a surgically clean surface, it will stand up to weather and water really well.
As mentioned, anything that doesn't like 400? F for 15 minutes has to be removed first.

I've acquired a Laser 2 stainless prop for my new to me alpha, I will be powder coating it black to cut down the anodic current to the aluminum leg.

 

[BAYLINER185]

Re: powder coating outdrive

I just used Krylon Gloss black on my BRAVO ONE drive to clean it up and make it look new.

The previous owner never wiped the drive off and it got water marks and stains that wouldnt come completly off. I cleaned the drive as good as I could then reshot it. It looks Awesome !

 

[j_cizzo]

Re: powder coating outdrive

well, needless to say, the drive would be COMPLETELY dismantled, seals and all. I know that a good powdercoat job is VERY hard. if i paint, i'm going with an etching primer and then imron, no rustoleum or spray bombs. the drive will be blasted, cleaned and the paint (or powder) applied. I was just questioning if the drive can handle an oven without the metal warping.

 

[Scaaty]

Re: powder coating outdrive

well, needless to say, the drive would be COMPLETELY dismantled, seals and all. I know that a good powdercoat job is VERY hard. if i paint, i'm going with an etching primer and then imron, no rustoleum or spray bombs. the drive will be blasted, cleaned and the paint (or powder) applied. I was just questioning if the drive can handle an oven without the metal warping.

Interesting. I would think even oven heat not a problem, but ya got thick, and thin sections, so might not heat evenly. Although slim, its a chance I don't think I would take. I'd do the Imron. Sprayed one of my Harleys YEARS ago, still tough as nails, and even the black sections doesn't change sheen much with wax. Tough stuff. And can be touched up, where as PC a different story (plus it adds thickness, where Imron won't)

 

[wire2]

Re: powder coating outdrive

well, needless to say, the drive would be COMPLETELY dismantled, seals and all. I know that a good powdercoat job is VERY hard. if i paint, i'm going with an etching primer and then imron, no rustoleum or spray bombs. the drive will be blasted, cleaned and the paint (or powder) applied. I was just questioning if the drive can handle an oven without the metal warping.

An outdrive is designed to withstand considerable physical forces from prop thrust and steering. The same design will also tend to prevent heat distortion. Take it to an established powder coat shop and ask. They will know what the oven will do to it. I'm confident it's not an issue. Thicker sections do not need to be heated right through, only the surface needs to be heated to fuse the powder.

For a comparison, new car bodies are dipped in water base electrocoat (primer), then sprayed base/clear and baked at 400? also. The sheet metal heats up to 275? in 6 min with no permanent distortion.
The doors, hood, & trunk, plus glass all fits after the oven.

 

[farmboy]

Re: powder coating outdrive

Coating submerged aluminum successfully does not equate to the intense labor of a TOTAL disassembly and abrasive blasting to "white metal" of ALL parts to be coated. That is what it would take for POWDER COATING a drive. The dry-powdered coating is applied electrostatically and then baked in an oven. the type of coating varies as does the temps required to cure the coating. It can be done and it could be durable but WHY?

As has been mentioned previously, surface preparation to receive the new coating is the key. I would not ever consider abrasive blasting on an installed drive. Once again, there are surfaces that do not do well with blasting and if the work cannot fit into a blast cabinet (such as a prop), why go to the trouble? That is not even considering what unhealthy things might be in the existing paint and primer that one would free up in the process.

A professional job can be had as follows:
1. Scrub the outside transom and drive with a brush and hot soapy water, then rinse.
2. Degrease any thick deposits with a water-soluble de-greaser (not gasoline).
3. Repeat step one.
4. Lightly hand sand the existing finish with 180 grit focusing on feathering chipped paint. Hand sand the existing paint with 220 grit with a thorough follow up with 320 grit.
5. Blow off the dust with filtered air and then tack with a lint-free cloth dampened with acetone (not gasoline).
6. Mask what does not get painted (including a cover on the rest of the boat and any cars you don't want painted).
7. I like an aliphatic polyurethane for the new coating as it is compatible with the original factory coating (all krylon type paints need to be completely removed) and is a two component mix for durability and gloss retention. It sprays well out of any functioning air spray gun. It is self-priming so a thin coat can be over-coated after about a twenty minute tack time and the finish coat about twenty minutes after that. Your back on the water after a 48 hour cure at 80F.

The only step in the process that abrasive blasting replaces is the hand sanding part and really, How hard is it to hand-sand that tiny outdrive anyway?

 

[CharlieB]

Re: powder coating outdrive

Yea, right, it's a pretty safe bet that FarmBoy hasn't sanded and painted an Alpha yet.

Give him time, someday he'll learn curves, flats and corners are not at all like sanding on a big ole car, no itty bitty nooks and crannys, like there is around an Alpha mounting bolts, or the front side of the upper gearcase.


Chanes are he'd be voting for firing up a sand blaster and hosing it off, that would be a whole lot easier than sanding it.

Squirt away with the paint, as long as the end result looks good and lasts thats really all that counts.

 

[farmboy]

Re: powder coating outdrive

Charlie,
Hope all is well with you. The very last thing I am looking for is an argument. After 30 years in the industrial abrasive blast and coating industry along with a degree in corrosion engineering and coating forensics, I am confident that I know just a wee bit bout the topic. All I gave in the info above is how I did my 888 and saved myself a bunch of time and grief. Blast away if you like, I'll pass. Thanks!

 

[flabum]

Re: powder coating outdrive

Powdercoat is indeed a great way to paint something, but I would'nt powdercoat an outdrive. The first nick will allow water to ge under the coat and begin massive corrosion. By the tim you see the corrosion bubble, the metal will be pretty well eaten up.

I'd prep the housing by bead blasting it, wash it with soapy water and rinse well, add alodine treatment, zinc chromate primer and paint (Imron). That is how I would do mine.

 

[j_cizzo]

Re: powder coating outdrive

Charlie,
Hope all is well with you. The very last thing I am looking for is an argument. After 30 years in the industrial abrasive blast and coating industry along with a degree in corrosion engineering and coating forensics, I am confident that I know just a wee bit bout the topic. All I gave in the info above is how I did my 888 and saved myself a bunch of time and grief. Blast away if you like, I'll pass. Thanks!

regarding the blasting, when I got my boat, it had some paint wear, so I scuffed, etch primed and used POR 15 to get through the season (I also applied the appropriate antifoul). This is a volvo DP-A outdrive, and although there isn't any corrosion yet on the leg itself, this is for preventative purposes. when I pulled the boat and powerwashed the hull and drive, some of the paint peeled off. I always had the intention of pulling the drive off and repainting it, i'm just looking for the best possible way. I'm now leaning towards the imron because like someone pointed out, i can touch it up, can't really do that with powder.

Understand that this boat is left at a mooring all season long, so making sure that drive is sealed and protected is of UTMOST importance.

Someone said 'clean it with zinc chromate", isn't that defeating the purpose? spraying a drive with a less-nobel coating? that in itself could cause corrosion, correct?

corrosion engineer? i guess i REALLY need to talk to you b/c i can't afford at the moment to lose this drive. so If i paint it, what do i do? Do i need to strip the drive to bare metal? i think at this point I do to remove buildup.

Thanks!

 

[j_cizzo]

Re: powder coating outdrive

Coating submerged aluminum successfully does not equate to the intense labor of a TOTAL disassembly and abrasive blasting to "white metal" of ALL parts to be coated. That is what it would take for POWDER COATING a drive. The dry-powdered coating is applied electrostatically and then baked in an oven. the type of coating varies as does the temps required to cure the coating. It can be done and it could be durable but WHY?

As has been mentioned previously, surface preparation to receive the new coating is the key. I would not ever consider abrasive blasting on an installed drive. Once again, there are surfaces that do not do well with blasting and if the work cannot fit into a blast cabinet (such as a prop), why go to the trouble? That is not even considering what unhealthy things might be in the existing paint and primer that one would free up in the process.

A professional job can be had as follows:
1. Scrub the outside transom and drive with a brush and hot soapy water, then rinse.
2. Degrease any thick deposits with a water-soluble de-greaser (not gasoline).
3. Repeat step one.
4. Lightly hand sand the existing finish with 180 grit focusing on feathering chipped paint. Hand sand the existing paint with 220 grit with a thorough follow up with 320 grit.
5. Blow off the dust with filtered air and then tack with a lint-free cloth dampened with acetone (not gasoline).
6. Mask what does not get painted (including a cover on the rest of the boat and any cars you don't want painted).
7. I like an aliphatic polyurethane for the new coating as it is compatible with the original factory coating (all krylon type paints need to be completely removed) and is a two component mix for durability and gloss retention. It sprays well out of any functioning air spray gun. It is self-priming so a thin coat can be over-coated after about a twenty minute tack time and the finish coat about twenty minutes after that. Your back on the water after a 48 hour cure at 80F.

The only step in the process that abrasive blasting replaces is the hand sanding part and really, How hard is it to hand-sand that tiny outdrive anyway?

oh, and BTW, regarding gloss retention, i really don't care how crappy this thing looks, I'll paint it pink if it'll protect it best.. so when you advise me, lets go for the most durable methode possible.

Again, Thanks a lot in advance!

 

[farmboy]

Re: powder coating outdrive

J Cizzo, A pink drive...now that would be different! The aluminum drive case all by itself is fairly corrosion resistant in the atmosphere. You are talking about protecting the drive while its submerged most of the time? Galvanic, not paint protection is the paramount concern I would think. A well applied quality coating will help insulate the metal and thus contribute to less corrosion risk but the coating alone will not be enough to protect the metal. I am not qualified to comment on anything but basic cathodic protection, but I do know that galvanic current has to be directed away from the drive or you will lose metal pronto. One of the neccesary ingredients for corrosion is electrolyte (water). The more mineral content (salt) in the water, the more efficient the electrolyte. It was mentioned above that all zinc anodes be in top shape and I agree as those sacrificial zincs are designed to be the first things to go. Whatever you do, do not coat the drive metal where the zincs mate up. Anything that insulates current from traveling between the drive metal and the zinc will render the cathodic protection they furnish useless. I have read about drives that were electrically bonded to provide additional protection but I am not familiar enough to comment. Dockside, dedicated cathodic protection for marine applications maybe an option that someone here might know more about.

 

[achris]

Re: powder coating outdrive

For a dockside boat that lives in the water, I would look very seriously at an impressed current protection system. Mercury make a system for their engine called Mercathode, I suspect VP would do something similar. It basically works by applying a current through the drive and the water to impair the loss of material from the drive. Merc do a great book on corrosion . If you send me a PM with your e-mail I'll scan it and send it to you.

Chris..............

Love the pink drive

 

[gene8084]

Re: powder coating outdrive

I have a volvo DP-A outdrive and it needs to be repainted so I was wondering about powder coating it. Apparently powdercoating is much more durable than paint, so I was going to have the whole thing powdercoated, otherwise I'd use etch prime with imron.

I've searched all over the web and emailed people have never gotten a response. so maybe someone here knows. can it be done? or will the heat from the oven alter the casting?

thanks

It's a big enough job just pulling it apart. If you don't need a complete disassembly, why go there.

While I was doing the bellows, gimble bearing replacement, and rebuild of Trim RAMs I sanded, dremeled, cleaned, primed and painted my 1974 Merc 888.

Rustoleum Primer & OEM Mercruiser Phantom Black Spray paint from www.Diversified-Marine.biz.

Before & After shots...

 

[achris]

Re: powder coating outdrive

While I was doing the bellows, gimble bearing replacement, and rebuild of Trim RAMs I sanded, dremeled, cleaned, primed and painted my 1974 Merc 888.

Rustoleum Primer & OEM Mercruiser Phantom Black Spray paint from "www.Diversified-Marine.biz

Before & After shots...

Gene,

You've done a beautiful job on that leg!!! Just one question.... You have a V8 in a relatively small boat, why the wing on the leg? Have you tried the boat without it? I generally find they produce way too much bow-steer for safe boating, particularly once the speeds up.

My 2c

Chris............

 

[gene8084]

Re: powder coating outdrive

Gene,

You've done a beautiful job on that leg!!! Just one question.... You have a V8 in a relatively small boat, why the wing on the leg? Have you tried the boat without it? I generally find they produce way too much bow-steer for safe boating, particularly once the speeds up.

My 2c

Chris............

Chris, The short answer is that's the way I bought the boat. I haven't taken it over 12 MPH yet.

I'm a a novice at this and unfortunately this "turnkey" boat I bought needed a great deal of tune-up work. I spent the first couple months having starter & alternator rebuilt, replacing the fuel pump, draining and cleaning the tank, plugs, cap, points, rotor, wires, dwell, timing, and rebuilding the carb.

Once I got it running I took it out in a small lake (with a speed limit) to id the source of some water I was getting in the bilge and test all the work I'd done. I ended up doing the transom repair kit route since I couldn't find the source and ran out of good weather in Connecticut. I think the source of the leak may have been the oil seal on the shift rod, but can't be sure.

Can you be a little more specific what I should look for in steering?

Last, it's a pretty heavy boat, but I can't explain why it was spec'd this way. It's a deep V hull. Weighs approx 2150 w/o the 302 and stern drive. Seems to have a 30+ gallon tank. I understand it'll do 40 MPH, but haven't had the opportunity to get it up on plane yet.

Hard as it was to stop for the season, I winterized a week ago and will have to wait for spring to work out the last of the tuning. I was stalling when quickly advancing the trottle.

Gene