Getting heavy scale off of the outdrive

[Chappydoc]

I went to Bass Pro and found Starbrite hull cleaner, which worked on the gelcoat. Although, it wasn't as quick as what was described from Mary Kate. I have a lot of deposit on the outdrive components, but I'm concerned about using anything too caustic (Mary Kate is Hydrochloric Acid 20%) on an area that has metal around it. Any ideas?

 

[Chris1956]

On-Off cleaner is bad for metal. I think that is what you used from Starbrite. It has 3 acids and some alcohol, again bad for metal.
Use some purple stuff and scrubby pads. If that doesn't get it, scrap, sand and prime and paint.

 

[Chappydoc]

On-Off cleaner is bad for metal. I think that is what you used from Starbrite. It has 3 acids and some alcohol, again bad for metal.
Use some purple stuff and scrubby pads. If that doesn't get it, scrap, sand and prime and paint.

Hi, Chris,

What 'purple stuff' are you referring to???
The rest of it doesn't sound very appealing to me!

 

[dingbat]

I have a lot of deposit on the outdrive components, but I'm concerned about using anything too caustic (Mary Kate is Hydrochloric Acid 20%) on an area that has metal around it. Any ideas?

 

[Chappydoc]

View attachment 350589

Dingbat,

Just ordered it. Hopefully, it does the trick!

 

[Chris1956]

Purple Stuff is the generic version of Castrol SuperClean. It is an alkaline cleaner and degreaser.

 

[poconojoe]

I hope it's just surface crud and not aluminum corrosion.
I once noticed a couple of tiny spots on my spotless drive were starting to corrode. Then I noticed the bonding wire had fell off the drive side. I fixed the bonding wire and it stopped. I used a little touch up paint to fix the tiny spots.

 

[Chappydoc]

I hope it's just surface crud and not aluminum corrosion.
I once noticed a couple of tiny spots on my spotless drive were starting to corrode. Then I noticed the bonding wire had fell off the drive side. I fixed the bonding wire and it stopped. I used a little touch up paint to fix the tiny spots.

I'll check into that. Thanks for the tip!

 

[poconojoe]

I'll check into that. Thanks for the tip!

Yep, without that bonding wire, the drive becomes a sacrificial anode since it's made of aluminum.
This might not be your problem. It's probably just covered in crud, but it's something to keep an eye on.