I need a bit of help painting an old motor and cowl

hi all. Not sure if this is the right forum so please feel free to move this post if need be.

I think I'm going to attempt to paint the cowl and lower unit on my '61 QD-22 10 hp this winter. I've never painted an OB before, so I'll take all the help I can get. For starters, I need to repair/repaint the fiberglass cowl. There are no major crack or holes in it, but there are a few spots where I can see the f'glass fibers, mostly along the edges. What should I use to cover/fill in these areas? Bond-o, or something similar? What type of primer/paint would be good for the f'glass cowl? Many have suggested Rustoleum products from the auto parts store, rather than the hardware store, any thoughts?
As for the lower unit, I've read several threads and I think I have the basic ideas as to how to do that. Any personal suggestions for what to use to remove old grease and dirt from all the nooks and crannies? I've heard oven cleaner works well, but I've never used it before. Also, should I paint over all of the drain/vent screws and other nuts and bolts? Should I remove all of the old paint and take everything down to bare metal everywhere, or only the areas that are loosest? If I leave old, solid paint on the LU can the zinc chromate primer used on the bare metal go over the old paint too, or should only use the ZC primer on the bare aluminum spots? Sorry for all the questions. Thanks for any and all help. No detail is too basic or small. I'm a total noob when it comes to painting. Thanks again.

Re: I need a bit of help painting an old motor and cowl

I'd use glazing putty or filling primer on the minor imperfections on the cowl. On the cowl, just be sure to use a primer that's compatible with the finish coat. I usually use acrylic enamel or lacquer. On the aluminum parts, it depends on how much work you want to do. You could strip it all down. I usually sand everything down smooth and finish with 400-600 grit paper (wet). If all the paint doesn't come off, you can use the zinc chromate primer even over the old paint. I haven't had any problems doing that. I clean everything before painting with odorless mineral spirits. A toothbrush works great in tight spots. In very difficult to access spots, use some spray carb cleaner - works great. I usually paint the drain and vent bolts to match. On other bolts, if they were painted originally, I paint them If not, I either remove them or mask them.

Re: I need a bit of help painting an old motor and cowl

If your motor is done for the season (which it may not be in Tallahassee), you could do what I did. I took my outside covers to a local shop and they ran them through their spray cabinet. My covers were pretty gunky and some of the original paint had worn off over the years. The spray cab cleaned up the parts really well without removing what was left of my original paint. I then covered the bare metal spots with self-etching primer followed by top coat followed by clear coat. I am totally new at painting but I must say that the results were excellent. I can't remember the cost of the cleaning, but I think it was around $30. It was without a doubt worth every penny since I didn't have to break out the toothbrushes and solvents for those hard-to-reach crevices. I haven't finished my rebuild yet, so I can't comment on the durability of my paint job, just the immediate looks of it.

Re: I need a bit of help painting an old motor and cowl

Thanks guys. I'll look into getting the cowl done first and work on the lower end after that. I thought about taking it to a paint shop so they could clean/blast it too, glad I'm not alone. I'm ho painter but I'll give it a go. I'll keep y'all posted.

Re: I need a bit of help painting an old motor and cowl

Blasting will definitely remove all of the old paint. You want something a little less aggressive if you don't want the original paint to come off such as spray cabinet cleaning. I believe it uses high pressure water and detergent to remove grease, gunk, etc. I'm not an expert in cleaning methods though, so you should ask around. I figured that if the paint was still on my motor after 47 years, then it would make a good strong base layer and I didn't want it to be removed.

Re: I need a bit of help painting an old motor and cowl

Go to nymarine.ca they sell paint and have painting tips there.

Re: I need a bit of help painting an old motor and cowl

thanks for the clarification yorab. I'd say 90% of the old paint is still on the LU, it's just dirty. I'd love it if it didn't have to go down to bare metal. I'm not trying to get showroom quality, or anyhting. I'd just like to spiff her up a bit. I'll keep everyone posted. I'll try tp figure out how to get pics up too. Thanks again.

Re: I need a bit of help painting an old motor and cowl

I did mine 2 years ago, to get the goo out of the tight spots I used laquer thinner and a tooth brush or a rag on a thin screw driver, I took the mount off and hung mine from the roof of the garage, just be sure that you aren't in the path of the garage door when it opens, yes there is a reason I know this.

I used Duplicolor paint from a auto parts store and then topped it with auto clear coat I had left over from painting my truck, turned out really well.

The biggest mistake newbie painters make is they think you have to strip the old paint which you don't, just scuff it good with some 400 grit and you are good as long as the old paint is still on good.

The second mistake is wanting to paint to fast before all the prep is done, prep is 90% of paint, i spent 10 hours on prep and maybe an hour actually painting.

If you have any bare aluminum on the lower make sure you use and etching primer also from the auto parts store, it doesn't take much but you have to use it.

For the cowl make sure you get all the lose stuff off, you might have to dig in pretty good to get it but if you leave lose material your filler won't stick.

I am not a glass guy so I would personnaly use bondo to fill, use a block when you sand it to keep it flat.