Painting DP-c

M

MotorheadTed

Seaman
Joined
May 2, 2011
Messages
50
I have stripped my outdrive to bare metal and am about to start repainting it. I am planning on first prepping with "aluma prep", then treating with alodine, followed by urethane primer and finally a urethane topcoat with hardener.
I had read somewhere that all pitting should first be filled. (I'm thinking epoxy, maybe JB Weld).
Anybody have any thoughts about this procedure, pro or con ?
Ted

p.s. I noticed that the top bearing retainer cap and the shift cover are made of a dark grey, blackish metal, probably magnesium. Can't imagine that would last 2 seconds in salt water !!! If it is mag, I think the prep chemicals would be different than for aluminum.
Anyone know for sure what that metal is ?
p.p.s. I am also starting another thread in the electrical forum re: corrosion on this drive.
 
Last edited:
C

cobalt252

Seaman
Joined
Jul 24, 2011
Messages
73
Re: Painting DP-c

MotorheadTed said:
I have stripped my outdrive to bare metal and am about to start repainting it. I am planning on first prepping with "aluma prep", then treating with alodine, followed by urethane primer and finally a urethane topcoat with hardener.
I had read somewhere that all pitting should first be filled. (I'm thinking epoxy, maybe JB Weld).
Anybody have any thoughts about this procedure, pro or con ?
Ted

p.s. I noticed that the top bearing retainer cap and the shift cover are made of a dark grey, blackish metal, probably magnesium. Can't imagine that would last 2 seconds in salt water !!! If it is mag, I think the prep chemicals would be different than for aluminum.
Anyone know for sure what that metal is ?
p.p.s. I am also starting another thread in the electrical forum re: corrosion on this drive.
Click to expand...


How to paint Volvo Penta outdrives, see http://forums.iboats.com/showthread.php?t=529870&p=3607909#post3607909
 
M

MotorheadTed

Seaman
Joined
May 2, 2011
Messages
50
Re: Painting DP-c

Cobalt: thanks for the link. Aluma-prep is the cleaner/etcher and alodine is the "chromate conversion coating " I just have to find out why they an epoxy primer instead of urethane.
I'll do a search for "painting magnesium".
 
R

Rusty S

Seaman Apprentice
Joined
Oct 17, 2011
Messages
32
Re: Painting DP-c

I had read somewhere that all pitting should first be filled. (I'm thinking epoxy, maybe JB Weld).
Anybody have any thoughts about this procedure, pro or con ?

Not trying to hijack the thread, but the"how to paint Volvo outdrive" thread does not speak to filling corrosion marks. I started a post some time ago asking this question as well. I am in the midst of repainting my DP-SM and have been filling marks/scratches from somebody elses former mess with automotive type glazing putty.
I have applied this prior to any chemical prep. Will this hold to metal?
My intentions are to continue in this manner, then prep with Metal Prep, treating with alodine, prime, and paint.
Don't want to continue in this manner if the glazing putty isn't going to hold....
Please help!!
 
M

MotorheadTed

Seaman
Joined
May 2, 2011
Messages
50
Re: Painting DP-c

Rusty; I don't remember where I read about filling pits, it wasn't in the thread you mention. I do think it's the proper thing to do, as painting over pits without filling might not fill the pitting completely, leaving air pockets under the paint allowing corrrosion to continue to develop. I know that epoxy as an adhesive/filler is the best material for the job, and every epoxy instructions I have read say to apply it to clean BARE metal. Also use a epoxy primer. I asked my local auto paint supplier why epoxy as opposed to other primers and he said because it is a non-poreus (sp?) coating so is a better water barrier
 
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