re painting out drive

rasbury

There are numerous threads on re painting drives, surface prep etc. and what types of paints to use. On mine, I have paint that is starting to bubble and its right in the area where the lower part of the foot joins the upper part, right above the prop. It looks like I would need to remove the bolts that hold that together to get in there are get that corrosion out and painted- will that likely cause the lower part to leak, should I pull it apart (not really wanting to do that) so I can reseal? I think if I pull the bolts, finish and put bolts back on the good way to go but don't want to solve one problem and create a much bigger one!

Handymans342

Ras, show us a picture

Handymans342

Randy. What kind of paint? I'm using rustoleum self etching primer and RO high performance enamel

Handymans342

You cant protect every square inch. Self etching primer means that the primer will adhere itself to the bare metal. Hopefully I will get to mine this week

Cableguy Greg

If you separate the drive, you will have to drain the gear lube and refill when finished.

rasbury

I will put some pictures up, was thinking of hauling it home this weekend. I don't think I need to separate anything, just remove the nuts. will get those pictures...

Michael T

Ras,  I agree. Splitting the drive would not be my first choice. 

rasbury

Sloooow down there guys- I'm talking only about removing I think it is two nuts on each side of that lower part of the lower unit, right above the prop -so I can get in there and sand and paint and get at the corrosion- I could do one side at a time so that the other side would hold it all together and then do the other- the question is if I back off the nuts, will I then HAVE to split that case apart and then re seal- surely someone else has run across this re painting- I just want to get all the corrosion I can. If I don't do anything, I assume at some point it will eat through the case so I have to do something either way!

rasbury

here are the pictures and you can see the nuts I'm talking about. The corrosion is only in this one area on either side of the drive. Also find it interesting it is all on that lower part only and the knock in the skeg is on the back edge and not the leading edge...must have dropped the drive to do that...and lastly, my boat on my "lift"!

Michael T

@ras, I agree you do need to address that corrosion and get ahead of it now! 

rasbury

yep, so now that I have the pictures up, see the nuts right there in the midst of corrosion area, can I take those off, even if one at a time, and not worry about the seal in the lower foot?

Handymans342

Ras, what kind of paint are you using? Don't waste your money on mercruiser paint

randy56

Ras, mine looked worse, first i took a high preasure washer to it with a roto tip, if you don't know what one is, they have a ball in the tip that rotates the water at high preasure. that got 90%, then i used a wire wheel on battrie drill, to clean up missed spots, then very little hand sanding, cleaned with hull cleaner,  freash water wash and dry it was ready for primer. also removed cooling tube, and the plastic covers on the cylinders, I did not take any SS bolts off, just taped them before paint.  to get in closer, and repaint. It is not a body shop job but looks good. Sprayed on primer and paint. 
Off subject, What are you pulling it with? I just bought a 99 ford f350 single wheel, 7.3 just for towing, but have not tryed it yet. My daily driver chevy half seem like it was to much load, and I was afaid to go to fast or interstate driving. Your rig looks good.

rasbury

Did you try it yet handy? I may do a little clean up/prep work but had planned to first, search the site for others comments. If I do not find a better answer get the merc primer and paint. Nice today, wish I had whatever now. Still concerned about getting the corrosion behind those nuts but no one is commenting on that.

rasbury

Oh and the truck is an f150, you can tow stuff with a ford (pole poke).

Handymans342

Remove the nut it won't hurt anything. There probably won't be any thing under it

randy56

I bought my paint at NAPA auto parts, be sure and tell them what your are doing the primer was just for alumium. They have many types. I bought the best and requested it. Rustoleum also has great products. just never tryed them on outdrive. That ethching primer sounds like the same product just in a NAPA can. Behind the nut, can remember how much room was behind there, fold sand paper? 

randy56

Another thought, I taped and papered the back-transom 2 ft wide on each side and prop, taped cylinders, and under the swim platform to prevent over spray. taped  stickers, nice day here also high of 22.

Handymans342

74 here. Why should I care if a little paint gets on the props? It will just ware off

Cableguy Greg

I would use zinc chromate primer unless you are going to use a specific anti fouling paint. If I trailered my boat like you do Ras, I would paint it with Merc Phantom Black paint.

http://www.amazon.com/Moeller-Green-Chromate-Primer-Outboard/dp/B000N8LR24

randy56

74 there, just trying to be neet and clean, poor Ras is not going to know what to do, anything will be better. cableguy must have had to do this before also, a freind of mine used those Merc paints with success.

Michael T

The Mercury paint will be fine on a trailer or lift. If you wanted to remove the nuts on the drive one at a time you would be fine. I have done that,  but I also looked up the torque specs for the bolts and re-torqued them to specifications because you can twist an aluminum housing with over torqued nuts. I have two torque wrenches one in inch pounds and one in foot pounds for all torquing needs. 

rasbury

I did a little prep work, mainly on the skeg as I hit that will a palm sander. The area right in between the two lower parts...while there are a couple spots that paint is peeling a bit, the couple of spots I thought a real issue, I'm not sure. It looks like what I took to be loosening/corrosion paint, might be casting parks of some sort? The paint does not come off like other areas with lite scraping.... 

rasbury

did find the etch/primer and paint- that primer is really "ruff" I assume you sand hat with some very fine paper before final paint? While it was not as bad as I thought once I got into it, the area that really had some stuff going on was where the exhaust boot connects to the out drive- really corroding here but not much I can do about that unless I pull it....


f

rasbury

I think I got at the most I could get at without pulling the drive off, and then you would have to take it apart to really do a 100% on it- if I have issue down the road that needs work and it gets pulled or when I do the bellows, I will take another look at what else I can do but for now, I will get this finished up over the next day or so. I did use the etch, at least from that manufacture and the Merc paint which both were on the shelf side by side at the marina so I'd think a good match up. I will put a final picture up plus a couple I took when it was sanded down and primed...

rasbury

oh, and one thing I forgot to mention....one area I had to sand, there is a stainless steel wire that has a torx screw into the side of the out drive. Looks like it come from a limit switch perhaps on the trim? One on each side. I could not get this screw out and twisted it off which about gave me a heart attack! Looks like I can just drill and tap another hole right next to the broken off screw....what does this do and is the position of it critical?

Handymans342

That is the grounding bond wire

Michael T

I'm sure you know how important the grounding bond wires are as anti corrosion links. 

rasbury

Well, to be honest, I don't believe do! I have heard the topic discussed but I don't have a clue as to the details. So, the wires on all the thru hulls, other grounding for the boat boils down to a couple of wires  bolted to the out drive? Geesh! It must have been corroded as to twist off the way it did.... So there are a couple of these back there I think and if they are corroded in their holes, I would suspect that grounding is not happening.....?

randy56

ras, old age in tough on memery, I will go look at my boat, and report back in a day or so.

randy56

Ras, light bulb came on I remimbered. those wire's are apart of a daisy chain ground, starting at the block, to gimble, to outdrive, ect.. Merc put them on there to try and help with galvanic corrosion. If any one of them are missing the drive will suffer. If you have to relocate, clean a spot to bare metal. where you rehook up the ground wire.