Hey /diy/
I recently purchase an older work boat and I have plans of re-purposing her has a weekend warrior fish killer.
This is going to involve a moderate amount of welding though, and I've spent no time on aluminum. Although not a welder by trade, I've spent years sticking, wire feeding, and brazing on steel and ss. I know aluminum is a different monster, but I don't feel like it's out of the realm of reality for me to learn on my own.
I'm comfortable with weld prep. My biggest questions are what kind of output voltage should I be running to get good penetration on 1/4" and 3/16" material? What size wire should I be running? I was looking at .030" 4043. Does my gas choice differ between when I'm running the spool gun vs tig? I was planning on running pure argon, but could I use C25 while on the spool gun?
I'm setup with an xmt350 and spoolmatic 30A, although since the boat doesn't fit inside my small garage shop most of the time the 30A will be hooked up to my trailblazer 325.
Any help is appreciated, along with general aluminum discussion.
>>1018420
What will you be welding onto your boat?
Cant really help with your question just curious.
>>1018429
I'm rebuilding one of the jet pumps because the old housing has a crack in it but the newer housings have a different mounting pattern and different OD. So I'm going to cut out a 2'x2' piece of the transom, patch it, and then cut out the proper mounting pattern. I'm also going to run hull stiffeners along the sidewall mostly for aesthetics, but to give a little rub protection to against trees and stuff when I'm moored up in a river. Plus there are a handful of small drill holes to fill.
Alright so a guy is selling this 16,5 ft aluminum hull for like 300 USD, it was for a project he never got around to. I'm visiting tomorrow to check it out. What do I look out for? It's home welded but he claims its very well done, so let's assume that it is.
I already know there are "pinhole" corrosion in the hull.
Only two pictures, sorry.
>>1018498
>>1018498
How thick is the hull? That's strange that there would be any serious corrosion on a boat that's never really been in the water or been hooked up to shore power. Aluminum turning to swiss cheese is talked about way more than it actually occurs so take a good look that is really the case. It does happen though, and if it has it's basically a pile of shit not worth buying at any price.
As for what to look out for- check and see if the seams are welded on both sides or just one. Welding both sides of major seams provides a lot of corrosion resistance to the weld and shows good craftsmanship. If it has a built in fuel tank, make sure it's not welded to the skin of the hull, that's a big USCG no-no and insurance issue should anything ever happen.
Also ask if he knows the alloy of the skin. Home builders occasionally use 6061 for everything because 5086 and 5052 are expensive. At 300 it's not a deal breaker, but 6061 won't hold up well to abuse in river settings, and will have greater corrosion issues long term.
>>1018512
I have no idea about thickness or alloy. The seller hasn't used it but it has been used before him. Fuel tank is not included, but I've got one already. Thanks for the double weld tip, I can't see based on those two pics but I'll check it out.
>>1018512
Wouldn't a good aluminum 2-component putty and some aluminum paint fix the swiss cheese issues?
>>1018521
Not in any meaningful structural way. Would it work for a few weekend preventing leaks? Probably.
People like aluminum because it is naturally corrosion resistant. When it does oxide it creates a self sealing oxide layer which prevents further corrosion. Pinhole type corrosion is usually the result of galvanic corrosion though which is caused by stray voltage from bad wiring or the contact of dis-similar metals instead of air or water contact. It is not always readily apparent because it can cause corrosion spots that are smaller than what you can see and also that are not on the surface of the material. In addition it is frequently non localized, meaning it could be in many places through out the boat even if it's not visible yet.
The skin of a small vessel is usually a key structural component, and that skin flexes under any kind of load. The aluminum oxide in these pinholes acts as an abrasive medium, grinding away more material and speeding corrosion further. Even with the addition of a filler it will still wear on itself.
When it fails catastrophically (technical sense) is dependent on how bad it is though. For your purposes it could well be far enough out to justify buying such a cheap boat. Especially if it comes with that trailer.
See if the guy is cool with you taking a very hard rubber mallet to it and see what happens. If it holds up just fine you're probably good for a while. Just don't take it offshore or miles from civilization
Bump for input from any welders
Visit boatbuilding and welding forums. Do Anons really not know such wonderful resources exist?
Not here. NOT HERE. Google is your friend. It's not possible to adequately inform you in one 4chan thread.
Start with Weldingweb. There are many aluminum weldors there. You can't do aluminum MIG with C25.
Visit the Miller website for free video MIG and other process tutorials and check the Miller forums too.
All you seek and more is there. Again since you couldn't be arsed to find them in the first place, see REAL WELDING FORUMS.
3M 5200 marine adhesive sealant, and aircraft fuel tank sealant are your friends. Remember they exist and get some to play with.
https://www.youtube.com/watch?v=V_MiGrL9350
BTW in Euroland and Oz it's common to run heavier aluminum wire through a short conventional MIG gun.
One thing you might not find quickly in forums is that you can easily shorten a Tweco style MIG gun by cutting the gun end in the obvious manner. Use the Tweco band clamps (they are cheap) because regular Oetiker clamps are slightly too bulky to fit between the gun handle halves.
>>1018564
Sorry to bump an old thread, but my boat is on the hard next to an aluminum hull sailboat that was once worth a fuckload, but is now fucked due to electrolysis ruining the hull.
It's not contact with dissimilar metals that causes this, its proximity to those metals. Your engine will be of dissimilar material, and it will be submerged next to your boat. Even if your wiring is on point there is still an electronic field in the water around your boat, hence the presence of sacrificial zincs. Don Casey writes a real great cheap primer on electricity and boats, if you're going for a metal hulled boat it's highly recommended to figure that shit out before you drop money on some boats with 4 different kinds of metal chilling in the water fucking eachother up (think aluminum hull, bronze thru hulls, steel motor components and copper in the bottom plate).
As far as welding goes, as a welder, aluminum is tricky. Its great when you can backpurge but I doubt that happened with the welds on that boat. You don't have a friend with a TIG machine you can borrow?
>>1019096
Not to mention why the fuck did you buy this massive boat and why do you need a huge protected cabin for just fishing around on a lake for the weekend?
>>1019098
Not him. But cheap boat?
Sometimes you can't find exactly what you want at the price you are willing to part with
Most boat repair is done with MIG and a spoolgun for light work. We repaired boats for the county and it goes much faster than TIG because you can lay down a lot more filler. I'd go ahead of the weldor and prep with a flap disk, knock out grossly loose rivets (they were small, riveted john boats) and otherwise knock off all the sealer, paint and corrosion. He'd weld the open rivet holes shut and weld over the loose rivets. It goes pretty quickly but for a large boat spools can get expensive. (Many weldors hunt filler at auctions etc and stash it to save money. DIYers can save mad cash this way.)
Impractical for large boats but if you can fill a small boat with fresh water that's a good way to find leaks and seepage.
OP has a nice mobile rig and when he's done he'll be proficient and can make money doing mobile boat repair. Pontoon boats with their large aluminium pontoons can be lucrative. He can also barter repair for boat parts. I suggest he read up on propellor repair and collect scrap props for practice. Prop repair can pay well and he already owns the equipment.
This and other threads may help and plenty of weldingwebbers have the same equipment as OP:
http://weldingweb.com/showthread.php?54214-Someone-school-me-on-marine-grade-aluminum
>>1019098
I generally work two weeks on two weeks off so weekend warrior was a bit of a misnomer. I normally run the Yukon, but the boat will see some road trips down to Prince William Sound too.
>>1019227
$25K for the boat and trailer. Twin 454s that both run well and the pumps are in pretty good shape. She's 33' long and 10.5' wide. Didn't think it was too bad of a deal.
>>1019236
Thanks for the link
>>1019385
If you liked that link, you'll love this:
http://www.boatdesign.net/forums/metal-boat-building/
>>1018857
but you obviously can't use CO2 in any form, you need argon or Ar/He mix, which is expensive...
Also aluminium wire is much weaker, so there may be wire feeding problems
>>1022120
I wasn't suggesting CO2. Plenty of crafty non-Amurricans run heavy aluminum wire through teflon liners and conventional MIG guns. Some of them think our spoolgun obsession is amusing.
Anyway, back to what OP owns:
Example search string for OP: "miller forums mig aluminum spoolgun" which will cover what he has.
MIG options are many. The most successful tracked fighting vehicle in history, M113, wasn't welded with a spool gun and is mostly 5083 alloy also common to boats.
OP needs to use larger wire rolls than a tiny spool gun will hold or he'll go broke buying wire.
http://www.thefabricator.com/article/aluminumwelding/al-gmaw-cc-or-cvr
OPs Miller should do both cc and cv.
Upgrade options:
OP can feed finer wire with a push-pull MIG gun. Miller and Cobra make nice units.
http://www.hobartwelders.com/weldtalk/showthread.php?26253-push-pull-gun-for-aluminum
He has enough money for that boat, so he has enough money for a Millermatic 350 etc with a push-pull gun of his choice.
https://www.youtube.com/watch?v=njBhsVaaRqE
Seriously folks, go to motherfucking WELDING forums. Lurk, learn, post if needed. I like helping people and have over 4,000 posts on Weldingweb. Unlike ephemeral 4chan threads, those remain as a resource.
Lincoln example so folks know what their site looks like:
http://www.lincolnelectric.com/en-us/support/process-and-theory/Pages/aluminum-feeding-detail.aspx
Includes Spoolmatic info:
http://www.boatdesign.net/forums/metal-boat-building/welders-aluminum-1196.html
Check this post and the aluminum boat in the avatar pic. Then tell me you can't push weld aluminum. Note the advantage of a smaller conventional MIG gun over a bulky spoolgun.
http://www.boatdesign.net/forums/metal-boat-building/new-welding-aluminum-5494.html#post31978
>>1022176
typo, delete "avatar".
