coating for aluminum

[jerry1865]

hello, i seem to remember something about a coating for a riveted aluminum hull that sealed up the inside. i cant seem to find it, does anyone know where it might hide?

also im thinking of using heavy duty pop rivets (closed sealing rivets, 1100 psi tensile strength)
ive got about 400 rivets to put in and about half of them dont have good access from the inside due to the additional structure that was added to the boat last year.
ive used these above the water line with good results,
mainly just looking for confirmation that they will do ok on the bottom @ 60 mph.
thanks in advance,
jerry

[sschefer]

hello, i seem to remember something about a coating for a riveted aluminum hull that sealed up the inside. i cant seem to find it, does anyone know where it might hide?

also im thinking of using heavy duty pop rivets (closed sealing rivets, 1100 psi tensile strength)
ive got about 400 rivets to put in and about half of them dont have good access from the inside due to the additional structure that was added to the boat last year.
ive used these above the water line with good results,
mainly just looking for confirmation that they will do ok on the bottom @ 60 mph.
thanks in advance,
jerry

It's called GluVit... 2 part flexible epoxy.. 2 years in my Tinny now and not a single leak. After a lot of debate over closed end rivets vs a bucked rivet I went with the bucked rivets. Like you, I had a lot of tight places to get into but I managed to make backers and twist a few of my buddies arms and got it done. I've since talked to others that went the closed end blind rivet way and they've all got leaks.

[Dave Strong]

It's called GluVit... 2 part flexible epoxy.. 2 years in my Tinny now and not a single leak. After a lot of debate over closed end rivets vs a bucked rivet I went with the bucked rivets. Like you, I had a lot of tight places to get into but I managed to make backers and twist a few of my buddies arms and got it done. I've since talked to others that went the closed end blind rivet way and they've all got leaks.

GluVit works great ours lasted 6-7 years just redid it last year again, way easyer on the ears,and body than trying to tighten up or replace rivits.

Dave

[jerry1865]

since ive never done the "bucking rivets", i must ask a silly question. is it ok to back up the rivet on the inside and nail the head on the outside?
if so i think i could get most of them.

due to reinforcing the hull last year (all welded) i have about a hundred rivets that cant even be seen without a mirror

i have just over 400 rivets to put in.

i really appreciate all the help. jerry

[Dave Strong]

since ive never done the "bucking rivets", i must ask a silly question. is it ok to back up the rivet on the inside and nail the head on the outside?
if so i think i could get most of them.

due to reinforcing the hull last year (all welded) i have about a hundred rivets that cant even be seen without a mirror

i have just over 400 rivets to put in.

i really appreciate all the help. jerry



Just guessing here Jerry but I am going to say no, if its any thing like when we change sled tunnels and add renforcments. Have you got some scrap aluminum you can try and duplicate the hull and see if it will work hammering them as you would like to do it??
I had a rivit tool for my air hammer that fit the rivit heads perfect but still just made a mess, wanted to slip off the head and just couldn't get the rivit tight.
Best of luck

Dave

[sschefer]

Jerry, is it safe to assume that since you've welded on this, it isn't a production boat like a StarCraft or a Lund. The production boats all use tempered aluminum that has a really nasty habit of cracking if you weld it.

If you're really stumped on how to fix this, give Phil Taylor at JetStream Concepts a call. He's in Yuba City, Ca. His website is http://www.jetstreamgroup.net/?lang=en&sub=home

Contact info is on the sight. I've done a lot of Tinny work and when I can't figure it out, I take it to Phil. He's pretty well known in the industry as one of the best there is. The work he's done for me has been nothing short of miracles. Kind of funny though, the Aluminum Recycle place is just around the corner from his shop.. If he can't fix it, you don't have far to go:cheers:

[blazer01]

jerry

what type of boat are you trying to repair? there are a few people around here that still have those riveted boats. seems to me when they do damage to them they beat the dent out wled up the braces qand fill the rivet holes by welding them closed

[jerry1865]

hi steve, it was a production rig, a 22ft cuddy cabin by sylvan in fact. and yes ive done a pretty fair bit of welding on her. yes it has had a nasty habit of cracking, ive had to refine my aluminum welding techniques a bit to prevent it.

my long term goal here isnt just to make this old tub perform way beyond what it was built to do,( ive already done that).
but rather i intend to use this boat as a learning /proving boat.

then when it performs like i believe it should i will build my own hull from scratch.

ive got most of the details worked out to that end.
back to the present, last time out she did 55 mph with the forefoot of the bow pushing 4 to 6 inches of water.
my center of gravity is only 6 feet from the transom with me in it.

i figure when i get rid of this hook, ill have the boat that i really wanted, then ill start building the new one.

thanks for the contact info. always good to have an expert in the address book

[sschefer]

Jerry, do you know the trick of sooting with Acetlyne?

[jerry1865]

yes , it helps alot it you use it as a temp guage.

here is a question that will be worth alot of money to me to solve, completely unrelated to boats tho.
i need to bend 2" aluminum square tubing without and distortion of the inside diminsions. it relates to a system that i designed and patented.
ive already got a roll bender, but it gives me some distortion and i have an object that runs inside with only .020 of cleareance.

right now my curved pieces have to be hulled out of solid mat. but if i could ever find a way to bend the tubing without distorting the i.d. i would be able to pass the savings on to my customers.

[blazer01]

steve

wasnt trying to mess your thread up.just wanting gain a little knowledge..and let you know how we fix our rivets

[jerry1865]

any and all responce (s) are welcome. and yes i have used that method to repair concetrated areas, however this area that im woking now involves appr. 440 rivets.

[sschefer]

:cheers:Ken, no problem, I got what you were saying. I've done a lot of tinny work and that method only works on non-production hand builts. One of the reasons they rivet the production boats is because they flex so badly. The rivets are more forgiving than welding. The darn stuff temper cracks in a heartbeat. I can weld it now that I have a new AC/DC Tig. Phil Taylor bailed me out a couple of times before I got it though.

[blazer01]

:cheers:Ken, no problem, I got what you were saying. I've done a lot of tinny work and that method only works on non-production hand builts. One of the reasons they rivet the production boats is because they flex so badly. The rivets are more forgiving than welding. The darn stuff temper cracks in a heartbeat. I can weld it now that I have a new AC/DC Tig. Phil Taylor bailed me out a couple of times before I got it though.

steve
amazing enough my boat is all aluminum and I had it powder coated it went into the oven (475 degrees) for 1 1/2 hrs and when we pulled it out if there was any stress points they are gone now.. However the boat was in better shape when we were completed

[jerry1865]

id sure luv to give this tub the same treatment. where could i get a boat this size powder coated?
about what would it cost?

[Forkin' Crazy]

I've bent tubing with little distortion by filling it with sand. That may not work with aluminum though...? Interesting thread! :)


yes , it helps alot it you use it as a temp guage.

here is a question that will be worth alot of money to me to solve, completely unrelated to boats tho.
i need to bend 2" aluminum square tubing without and distortion of the inside diminsions. it relates to a system that i designed and patented.
ive already got a roll bender, but it gives me some distortion and i have an object that runs inside with only .020 of cleareance.

right now my curved pieces have to be hulled out of solid mat. but if i could ever find a way to bend the tubing without distorting the i.d. i would be able to pass the savings on to my customers.

[blazer01]

id sure luv to give this tub the same treatment. where could i get a boat this size powder coated?
about what would it cost?

Jerry
You could check with some of your local mfg's they may be able to do it. I use to work on the equipment. My boat is 17 foot long and only 56 inches wide. The place that did it well we kinda traded work for him to wash it in acid and put the powder on and bake only cost me 200 bucks...

[sschefer]

steve
amazing enough my boat is all aluminum and I had it powder coated it went into the oven (475 degrees) for 1 1/2 hrs and when we pulled it out if there was any stress points they are gone now.. However the boat was in better shape when we were completed

That's the cool thing about aluminum. At somewhere between 425 and 525 it tries to return to it's previous state. Lot's of auto repair guys fix aluminum dents with a heat gun. Not so easy on a boat since the heat spreads and dissapates to quickly.. So when it was in the oven did the dents and warps subside?

[sschefer]

I've bent tubing with little distortion by filling it with sand. That may not work with aluminum though...? Interesting thread! :)
I've heard it can be done with air pressure and heat. Never seen it or done it myself, just heard it through the rumor mill.

[blazer01]

That's the cool thing about aluminum. At somewhere between 425 and 525 it tries to return to it's previous state. Lot's of auto repair guys fix aluminum dents with a heat gun. Not so easy on a boat since the heat spreads and dissapates to quickly.. So when it was in the oven did the dents and warps subside?

Steve

actually the boat was brand new(never seen the water) so honestlly i cant answer that. as far as if it made the aluminum any weaker i dont think so i put my 2.4l 200 merc on it and been running it for 2 years now..there is no cracks in any of the welds.(however i had it custom made due to the fact that i did not want it to have a HP limit on it)

[jerry1865]

filling tubing with sand, i know it works for round tubing , but it has a bad effect on the square tubing.

powder coating...i have a shop here local that powder coats my mobility systems. everything but the aluminum tubing.
but they cant handle anything even close to my boat.

[Forkin' Crazy]

Ah OK. Just an idea because I really didn't know. As far as heat relieving stress, it probably annealed the aluminum. It should harden back with time depending on the alloy. When I worked on aircraft we had some special rivets that were so hard you couldn't buck them. We had to heat them with a propane torch to anneal them before use. You had a time window to get them in, other wise we had to anneal them again.


filling tubing with sand, i know it works for round tubing , but it has a bad effect on the square tubing.

powder coating...i have a shop here local that powder coats my mobility systems. everything but the aluminum tubing.
but they cant handle anything even close to my boat.