Pitting/corrosion on jon boat bottom

Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
315
Thanks everyone for the reply’s.
Yall can tell me if I screwed up the first time I pulled the floor. I was told as far as the pitting to hit it with a brush a little and fill in with marine J.B. Weld. Then I put weather striping on the cross members for a barrier. I just finished taking it all apart and where the stripping was is now black. And my memory must be going because most of the pitting was under the plywood which I now thing is treated. Here’s the pictures of what I got. So no need for vinegar and all that? Just clean and go back with plywood? I wish I new what to call the stuff on the old floor it’s almost like paper but pretty tough and non slip. The white stripes is the weather stripping. The other white stuff is the J.B. Weld.
 

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Bob Sander

Petty Officer 2nd Class
Joined
Nov 29, 2021
Messages
115
Honestly, I think you're kind of psyching yourself out and overthinking this.
I *THINK* someone at some point used some pressure treated ply in there at one point and done some (minor) damage.
Now you can throw some JBweld (or whatever) into the pitting if you want, but more than likely you will be vacuuming that up along with the dead leaves next Fall when you do your annual cleaning. In other words, it's not going to last very long. I can't tell from the pics how deep the pitting is but if it's really deep and concerns you then you can mig over it or even drill the pit right through and rivet it. If you don't have a mig setup then bring it into a shop and have them do it. A bit of aluminum welding/filling is not very expensive.

Less deep pitting.... don't worry about it.

Personally speaking, I wouldn't do a floor in there. I would sand blast it out and place riveted bench seats back in there (you can tell there were standard bench seats in there which some one hacked out at some point) and paint it a nice pleasing color.... but hey... it's your boat, not mine. If you want the floor though then yeah... the weather stripping is not a bad idea. It will keep a squeaking and rubbing down to a minimum.
 

Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
315
Honestly, I think you're kind of psyching yourself out and overthinking this.
I *THINK* someone at some point used some pressure treated ply in there at one point and done some (minor) damage.
Now you can throw some JBweld (or whatever) into the pitting if you want, but more than likely you will be vacuuming that up along with the dead leaves next Fall when you do your annual cleaning. In other words, it's not going to last very long. I can't tell from the pics how deep the pitting is but if it's really deep and concerns you then you can mig over it or even drill the pit right through and rivet it. If you don't have a mig setup then bring it into a shop and have them do it. A bit of aluminum welding/filling is not very expensive.

Less deep pitting.... don't worry about it.

Personally speaking, I wouldn't do a floor in there. I would sand blast it out and place riveted bench seats back in there (you can tell there were standard bench seats in there which some one hacked out at some point) and paint it a nice pleasing color.... but hey... it's your boat, not mine. If you want the floor though then yeah... the weather stripping is not a bad idea. It will keep a squeaking and rubbing down to a minimum.
I appreciate the comments. Yea I mess around on the internet and read a bunch of different things that had me all confused. I want to keep a floor over the cross members to disperse weight. Here I go again but I’m afraid I might loosen the old rivets walking directly on the bottom. I drift fish and run jug lines, etc. so we enjoy the extra floor space without the middle seat.
I appreciate your help talking me down. I just new I was going to mess up and the thing rot right in front of me.
All the other boats I’ve had where fiberglass. This is my first aluminum jon boat.
 

Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
315
Agree with others. As far as I know, if you get rid of what ever acid or chemical is or was causing the corrosion (sand blast or soda wash... etc) then that's as far as you need to go. People of course paint their aluminum boats to beautify, but I haven't heard of people treating aluminum to protect from (fresh) water unless it's going to be used with some corrosive chemical.

Untreated aluminum will last DECADES in fresh water without anything on it. Heck, we just sold a 40 year old 14 foot aluminum boat with the (raw) aluminum in pristine condition. Of course we redid the transom wood and seats over again probably about 1/2 a dozen times over its life.... just used regular 3/4 ply.... nothing special.
Got flooring material today. Going to give the boat a bath tomorrow. I have a good pressure washer. Do you think that would be sufficient?
 

Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
315
I want to thank everyone for there help. I really appreciate it. This is an awesome forum. When I first got the boat for a project I would not have been able to repair and service everything on the motor from carburetors to prop without all the help. Now I’m running wot thanks to the forum.
 

Grub54891

Vice Admiral
Joined
Jun 17, 2012
Messages
5,914
Got flooring material today. Going to give the boat a bath tomorrow. I have a good pressure washer. Do you think that would be sufficient?
Pressure washer will be fine but neutralize the hull first with backing soda or the like.
 

Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
315
Just a few minutes, scrub it around a bit and have half a beer.
I had to put off the boat and take care of other things. I have cleaned it up then used baking soda and scrubbed it with a regular house broom. Now I have bare aluminum in some spots and small pitting. Can you give me advice as to should I cover it with paint etc. to protect it or strip the entire bottom now and paint or is it fine the way it is. When I’m done the boat will be protected by a cover now. I appreciate any further advice. Thank you.
ps. The more I clean the more I find. Here’s a picture were I’ve found rust , it’s in a few areas. I figured out the bottom was painted green originally then there’s a rough coat of something none skid that’s black.
 

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Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
315
I had to put off the boat and take care of other things. I have cleaned it up then used baking soda and scrubbed it with a regular house broom. Now I have bare aluminum in some spots and small pitting. Can you give me advice as to should I cover it with paint etc. to protect it or strip the entire bottom now and paint or is it fine the way it is. When I’m done the boat will be protected by a cover now. I appreciate any further advice. Thank you.
ps. The more I clean the more I find. Here’s a picture were I’ve found rust , it’s in a few areas. I figured out the bottom was painted green originally then there’s a rough coat of something none skid that’s black.
Yeah there’s small pitting all over I can see it now with out the dirt. Lol
 

Grub54891

Vice Admiral
Joined
Jun 17, 2012
Messages
5,914
At this point it almost looks like it needs to be sandblasted or walnut shell blasted to see the extent of the damage. Patching just what you see now isn't the best route. Looks like someone coated it over before to get it looking better/stop leaking.
 

Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
315
At this point it almost looks like it needs to be sandblasted or walnut shell blasted to see the extent of the damage. Patching just what you see now isn't the best route. Looks like someone coated it over before to get it looking better/stop leaking.
I went at it again with my pressure washer yesterday. This time way more aggressive. I removed almost all the black coating. Left what looks like some of the original paint/primer. The rest is bare aluminum. There’s some light rust spots across exactly where the middle seat used to be. And a couple of small spots in front of the clogged up channels I found where it couldn’t drain. I used a screw driver this time and found everything from dirt and leaves to rocks , big rusted hooks and lures clogging the channels under the cross members. I don’t have a blaster. I’ve looked at the little hand held but they don’t look very reliable. I can hit it again with my gas pressure washer with a zero degree tip this time. If there is a weak spot I’ll find it with that. Lol The boat is a 1983 16/52 Monark. Probably cleaner than it’s been in 20 years. I feel fortunate it’s in as good of shape as it is. I’ve put it through the test with the 40 hp running on some rough water. I thought I was going to have to stop and pick my teeth up a couple of times. Lol
And hasn’t leaked, yet anyway. Sorry I got off subject.
I’m in a small town but there’s a metal fabrication shop here the does aluminum. They repaired a crack for me when a tree fell on the boat. I can see if they’ll blast it and if it’s going to kill my boat funds.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
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47,537
Find a local sandblaster

I used to spend weeks with a small hand held working on rust cars when I was building hotrods in the 80s and 90s. Then i found a local sandblasting company that only charged $200 to do a body and frame

Considering beer, sand, etc, it was not only a wash financially, it was done in 2 days
 

Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
315
Well I’ve managed to spend a few hours on the boat with a rectangular sander and a mouse sander along with a wire brush. First I sealed off the intake box on the motor because I know some of the dust will get past the cover and the cowling. (Blowing it out with the compressor as I go.)
When I mentioned looking into having it blasted I got that you have a shop full of tools look from the Admiral. Lol
Ive got about 1/4 down to bare aluminum. Probably going overboard. When I get down to the primer in some areas it’s pretty solid like I could paint over it. After sanding I’m going to seal all rivets, let that cure then after a final wipe down hit it with Rus-Oleam professional aluminum primer for 2 -3coats then their professional high performance enamel. Thinking about some type of sealer before I declare finished So I can put the floor in.
I’m having to work outside so I’m working between the winter weather here in Texas. Had to put the cover on her this evening for the next rain. I was getting ready to start the other morning when I heard a loud pop right next to me and I found my rear glass in my truck completely shattered. Looked like it exploded from the inside. Don’t know what caused it. So that eat up my sanding time that day.
 

Grub54891

Vice Admiral
Joined
Jun 17, 2012
Messages
5,914
I was getting ready to start the other morning when I heard a loud pop right next to me and I found my rear glass in my truck completely shattered. Looked like it exploded from the inside. Don’t know what caused it. So that eat up my sanding time that day.

That has happened around here in the past. The vehicles were sealed to tight, and the sun would heat up the interior expanding the air and blow out rear windows. At least that's the reason I heard.
 

Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
315
Just my opinion, but once the boat is clean just use it. I don't think your doing yourself any favors with all that sanding ect.
I’ve been finding a few spots of surface rust under the coating I’m taking off. Along with more small pitting. I want to put something on it that’ll put a stop to all that. I admit I do over think and worry to much about my boat but I need it to last me as long as possible. My wife calls my boat my girlfriend. Lol
 
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