Which type of aluminum to buy??

Date 06-09-2012 19:13 Edited 06-10-2012 16:15

#1 - Call the boat manufacturer for their recommendation on the type of aluminum to use.

#2 - 3/16 aluminum weights about 2.6 pounds per square foot. You can do the math.

#3 - I used to buy more material than I needed for the job. All I did, was end up with a pile
of stuff that will be around here forever.

#4 - There are special blades for nonferrous metals. Look around online for info on the proper
way to use them. You're going to need to use the right blade lubricant when cutting aluminum.

edit = grammar correction

By Chris2626 (***)

Date 06-09-2012 19:49

as far as weight goes that freaking nothing. Thanks

Gonna try calling the manufacture next week and see what they say.

I was thinking the same buy more then what I need because hell if it ends up being say 120 dollars for a 4x8 sheet then That would be worth it. I'm sure i could use it down the road.

Do they normally sell by 4x8 sheets like they would for ply wood??

By Northweldor (***)

Date 06-09-2012 21:02

Don't know about 3/16" since my supplier doesn't carry it, but his price for a 4'x8' sheet of 5/16" - 6061 was almost $500! Better stick to ordering what you need.

By Cumminsguy71 (*****)

Date 06-09-2012 22:24

Call and ask about the 4x8 sheets. They sell aluminum this way, I've checked on it for my truck bed but it was going to cost me $1000 or more.

By meanstreak (*)

Date 06-09-2012 21:33

You want 5052 alum. You should not have warping issues with 1/8". Use a lot of tacks.5356 would be a higher strength wire.4043 would more crack resistance. But in your application both wires would be fine. 3/32" size would be a good size wire.

By Chris2626 (***)

Date 06-10-2012 02:47

Thanks I just priced a 4x8 sheet and yes i will stick with what I need only. Understand though this pad has to be welded solid i can't allow any water to fill it up when running or taking off. Do you mean put a bunch of tacks then weld it solid? Friend of mine has a mig gun he's gonna help me with it. I'm really leaning towards though going with 3/16 inch plate because it is very important to keep this thing totally flat, I'll probably have to tack it all up and then weld a little and walk away to let it cool. I have also thought I should back step it as well to keep it as straight as possible.

By Chris2626 (***)

Date 06-13-2012 22:37 Edited 06-13-2012 22:40

I called ALWELD the builders of my boat, I asked what grade aluminum the boat is because i wanted to weld some stuff to it they didn't tell me the grade which aggravates me but said I could use 5052 or 5005. Guy I work with is gonna let me use his mig gun and he says the wire he uses is 4043 and has never had any problems with it. He said that 5052 I think it is is harder to weld with mig something about it is a harder aluminum and is better to be tig welded because it needs so much heat.

Whats the deal with 5005 is it a softer aluminum?? Where is there a chart that describes these different types of aluminum??

Any thoughts on what the guy at work is talking about should i go with the other recommended aluminum??

Just read where Mcmastercarr.com that on there site says 5052 is easy to weld do others agree?

Thanks
Chris

By aevald

Date 06-13-2012 23:21

Hello Chris, I have a chart from Alcotec that lists the 5052 and the 5005 sheet alloys on their filler metals chart. I believe that all of the 5052 that I have welded has been done with the 5356 alloys. According to Alcotec, 5052 is better served by welding it with the 5356 wire, the 5005 according to their chart, isn't really a good choice for being welded by either the 4043 or 5356 alloys of wire (they make other suggestions for better suited fillers). there are some ductility loss issues when it is welded with the 4043 filler and the 5356 doesn't receive very high marks in many areas either. All of the better marks come from using the 5052 base metal and welding it with the 5356 wire according to their rating system. You will find the information that I have pulled this from at: www.alcotec.com I thought that I had some other information, but I can't find it right now. A lot of this is pretty ambigious as it might be splitting hairs with regards to selection and application, you'll likely just have to make the final decision for yourself. Good luck and best regards, Allan

By Chris2626 (***)

Date 06-13-2012 23:39

i guess i'm gonna go with what my friend swares by which is the 4043 wire with the 5052 plate may pick up a roll of the 5356 as well to try out. Just need it to stick so I can run at around 65-70 mph I'm hoping hahaha

By DaveBoyer (*****)

Date 06-14-2012 02:49

The information I have from ESAB shows 4043 being the choice for MIG welding 5005 or 5052 to themselves or each other.

In My experience, 4043 runs a whole lot nicer than 5356.

If You use 5356 MIG for anything, be sure to have plenty of scraps to get it dialed in on.

By Chris2626 (***)

Date 06-14-2012 03:30 Edited 06-14-2012 03:37

Thanks Dave probably best to just stick then with the 4043 wire like my friend said, gonna try and get the aluminum this saturday and hopefully be able to do this the following weekend so I'll be sure to take some pictures.

I forgot to add now i do want to weld some angle aluminum as well when building this pad so the boat will track better. After some searching doesn't look like I can get a 5052 angle
all the angle is like 6061 and up on the numbers. I need to call that boat builder again and ask what is the grade aluminum since they really never told me.

I mean if I weld this 6061 aluminum to my hull am I gonna maybe experience cracking or what? is the higher the number the harder the aluminum?

By DaveBoyer (*****)

Date 06-14-2012 03:35

You MAY be able to get it, but angle & other structural shapes are usually 6061.

Will the angle be above or below the water line, and fresh or salt water?

By Chris2626 (***)

Date 06-14-2012 03:39

yes it will be below the waterline running both fresh and saltwater but I do plan on repaint the bottom after all this is done. I may do some test runs in fresh water then take it out and paint it.

By DaveBoyer (*****)

Date 06-14-2012 04:11

Don't use 6061 below the waterline, particularly in salt water, and especially if You leave the boat in the water.

Try to match what the rest of the hull is made from, at least stay in the 5xxx group.

By Chris2626 (***)

Date 06-14-2012 11:35

The boat is always pulled out and put on a trailer, this stinks if i can't get 5052 then I may not be able to build this pad

By Chris2626 (***)

Date 06-14-2012 22:54

guess I won't be using the angle like I had hoped, Just gonna have to build this pad a little different now and will just have to learn more how to drive the pad. The angle was to help it track better in the water and not slide off the pad so easily

By aevald

Date 06-14-2012 23:09

Hello Chris, the beauty of a material such as 5052 is that it is readily formable, you could have some sheet sheared and formed to make up angle, channel, or many other shapes that you deem necessary. The only thing lacking when you do something like that is the sharp outside corners of your formed pieces. Best regards, Allan

By Chris2626 (***)

Date 06-14-2012 23:44

Thats not a bad idea, where i work there's an old brake I'm betting it's at least 8ft in length, so if this stuff can bend that easily then I may see about doing that or ask the guys I buy it from if they have a brake and if they could do it. Thanks I'll go that route then. I would only need the sides to be bent up about a 1/2-3/4 of an inch is that still possible to bend that little to a 90????

By aevald

Date 06-15-2012 00:25

Chris, that is dependent upon the die opening width and the punch radius. If you need a 1/2" or 3/4" flange length then short of getting creative you will need to have either a 1" or 1 1/2" bottom die opening. Fortunately the 5052 is pretty forgiving when it comes to cracking so I believe you can use a fairly small-radius top punch and not have issues. Good luck and best regards, Allan

By Chris2626 (***)

Date 06-15-2012 01:39

I'm gonna have to ask someone at work more about this because I really don't know much about the brakes, if the place i buy the aluminum from has a brake it maybe worth having them do it. Thanks Allan

By rcwelding (***)

Date 06-10-2012 02:06

I use a carbide tipped blade in my skill saw... I have cut a pile of 1/4 aluminum with that saw.. I buy a good 8inch wood blade at my local hardware store 10 to 15 bucks.. I can get about three full rips out of a 10 foot long 1/4 thick sheet or a bunch of small cuts..!!

USE A FACE SHIELD....!!!!!!!! The little flakes don't hurt from the speed but they are HOT..!!!!

By DaveBoyer (*****)

Date 06-10-2012 03:46

I too have used normal carbide wood cutting blades in the skilsaw, mitre saw and table saw for cutting aluminum.
The Skill worm drive "77" saws run slower than the spur gear saws, this helps.
A wax type blade lube would help, as the 5xxx will be a bit "stickey", but You can cut it dry.

The face shield is a must, wear Your safety glasses under it.

Other 5xxx alloys that would work are 5083 & 5086. Do You know what the hull is made of?

By Chris2626 (***)

Date 06-10-2012 03:59

no doubt I'll have a mask safety glasses and a shield and long sleeve shirt and gloves. I can't stand cutting or grinding on a aluminum.

By aevald

Date 06-10-2012 04:57

Hello Chris, in my neck of the woods 5052 is commonly used for boat building and is often referred to as "marine grade" aluminum (not a standard term, yet we all know how that goes). It is readily formable and relatively crack resistant. As to cutting it, everyone has given you great suggestions about using a wormdrive skill saw or comparable unit. I will often use a fairly high tooth count carbide blade and rub it with beeswax or other types of wax, keeps it from getting sticky. X's 2 on good personal protection with all of the chunks and debris flying around when you're cutting.

One of the other posters suggested using plenty of tacks prior to beginning your weld-out. Aluminum just loves to crawl around, so if you would like to minimize the "oil canning" effect and keep everything just a bit straighter, follow his suggestion. If you sequence your weld-out by running relatively short beads in a pattern similar to a torque sequence for an engine head this will possibly aid to minimize distortion.

By chance are you adding a "trim tab" to the rear bottom of the transom of your boat? Lots of aluminum boat builders in our part of the states use an extended bottom skin to allow for bending of it to help to adjust the plane of the boat. Many of the old speed boats actually had a hinged piece with turnbuckles that could be adjusted to accomplish this sort of thing. Keep us posted on how you do on this project. Pictures would be great too. Good luck and best regards, Allan

By Chris2626 (***)

Date 06-10-2012 14:03

Thanks Alan,

Little more detail about what I'm doing and why. Two weekends ago I went to the next town over where i heard months ago about a boat club that drag races on the river well I went and drag raced my 15x52 alweld aluminum boat with a 50 tohatsu on the back. I got smoked by all of them but still had a freaking blast. I'd say some of the nicest dang racers I've ever come across. If you heard of the guy Glenn Hopkins well you know he builds a kicka** propeller and this is the guys who has been telling me how to make my boat faster.
My trim tabs are to dam short/long width wise so having to bend them down so much to get the front end down is creating tons of drag. The tabs across the back well act like a step and I will be able to bend them down so little and get the same affect but will be more speed.

He said to build a pad which will increase speed yet still keep the boat as a normal everyday fishing boat. He also said to find some piano hinge which is on order right now from Mcmaster-carr.com and I will make adjustable trim tabs that stretch across the entire boat. I will cut a V into the tabs so the motor can trim down into the tabs. I think what I'm gonna do is weld the piano hinge to the transom.

Back to the pad I was told that I should probably drill some holes for plug welds if i weld the plate to the center chime because i may experience some vibration with 1/8th plate so this was another reason I was gonna go with 3/16. i've welded aluminum for a couple years but been a while since i have so I need every advantage i can get so it will probably be 3/16 I will go with.

Found out about a 75 evinrude short shaft up the road from me a bit and gonna go look at this next weekend it would be perfect for my boat and there capable of well over 100 horses so that should make for lots of fun.

By aevald

Date 06-10-2012 14:55

Sounds like you've found a new-found form of fun for yourself. Get out there and have a blast and good luck. I am sure that a lot of those folks will have some very innovative suggestions for adding speed and handling for your boat. Back when my boys were into motorcross heavy-duty I learned a ton from a lot of different "racing dads and moms" and we had a blast too. Good luck, best regards, and stay safe, Allan

By Chris2626 (***)

Date 06-10-2012 20:11

Thanks these guys are safe they told me I had to wear a helmet have a good life jacket and have a lanyard kill switch that works. I also had to wear long pants and long sleeve shirt closed toe shoes and boy was it HOT but you forget about the heat when you're having so much fun. Growing up I always wanted to do some kinda racing but me and my parents could never afford it and this club makes it so that literally anyone can race from a 15 hp to a 75 hp motor, fishing boats hydros what ever they just want people to have fun and to get involved. So yeah I'd say I'm absolutely hooked.

By Chris2626 (***)

Date 06-16-2012 22:58

Allan I just bought me a used 75 Evinrude motor it's a 1975 which I'm gonna rebuild and hop up. I'd like to know there are some parts on the motor that are a little corroded and was to know is sandblasting way to harsh on cast aluminum? What would be the best method to get the old paint off and get it cleaned up?? IU know I could sand it by hand but blasting always did great to get into tight areas.

Any thoughts??

Thanks
Chris

By aevald

Date 06-17-2012 05:49

Hi Chris, I generally use a glass beading machine, a little less aggressive than a true "sandblaster", yet a sandblaster if used with due caution will work just fine too. Just be sure to be very thorough in cleaning all of the parts with solvent or some other sort of washing regimen when you get done with blasting them. The Evinrude sounds like a good one for you to get your feet wet on(please pardon the pun). Good luck, enjoy, and best regards, Allan

By Chris2626 (***)

Date 06-17-2012 17:13 Edited 06-17-2012 17:28

Lets see if this picture thing will work, this is what the motor looked like yesterday when I brought it home and right now it's in pieces I still gotta remove the power head then it will be pretty much disassembled

I got these to load, these were taken by the other owner before i bought it and some reason couldn't get my pictures smaller

Attachment: ev10.JPG (564k)

Attachment: ev11.JPG (556k)

By Chris2626 (***)

Date 06-18-2012 03:01

Another question for ya Allan since you seem to know a lot. I ended up having 6 bolts break off in the mid section of this motor, these bolts are stainless but are corroded into the aluminum pretty good. This is a cast aluminum what would be the best way and safest way to get them out?? I thought about taking it to a machinist because the mid section is like GOLD and don't want to screw it up. I used a ton of PB blaster before I tried to unbolt it but it wasn't enough. Any thoughts?

By DaveBoyer (*****)

Date 06-18-2012 04:26

You may have no choice other than drilling them out. If the holes are threaded, there is a good chance You will have to Helicoil them.

In spite of having a little chunk of zinc or magnesium on the cavitation plate for galvanic protection, the combination of aluminum in contact with stainless becomes a galvanic cell when wet with an electrolite [salt or brackish water]. This causes the corosion that binds the bolts into the holes.

When You reassemble the motor You need to use Lock Tight or Teff Gell to reduce the chances of galvanic corosion.

This applies to all hardware that is bolted to Your aluminum bolt. In addition, any metals other than aluminum need to be seperated from the aluminum with an insulating spacer [plastic].

The best method is to use plastic spacers and washers and thin plastic tube around the bolt to eliminate contact with less noble metals.

Never Sieze will not do the job.

By aevald

Date 06-18-2012 05:19

Hello Chris, you may need to go the route that Dave suggested. However, before you consider only that you may wish to try using the GTAW process and some stainless filler rod. In the "tricks of the trade" section there are a few threads where folks have included tricks for using welding as an option for sheared/broken bolts/taps/etc. I like GTAW for my removal tool on broken items providing that they aren't too deeply broken off or too small, although I have removed broken machine screws as small as 4-40's with that method.

Since you have aluminum as the base material and it doesn't readily combine with the stainless when you are welding on the stainless portion there is a certain amount of safety from damaging the aluminum. Clean the area with your stainless wire brush as well as possible and then start applying small stainless beads around the outer perimeter of the broken stainless bolt and spiral into the center of the broken bolt. Continue to do this in layers until you can grip the built-up portion with vise-grips or other suitable type tools. You can also weld and build-up in a similar fashion and incorporate a washer into the welding process and then weld a nut to the washer and then use a wrench to back-out the broken bolt. However you build-up and grip the broken portion, the heat from this welding will generally aid in breaking the bolt free and with a bit of lube(paraffin or bees wax melted onto the area after welding, aerokroil, WD-40, PB Blaster, or other lubricants) by working the broken bolt back and forth and having a bit of patience you will generally be able to safely remove the broken piece.

I'll see if I can find some of the examples of this and include them here to give you an idea. Good luck and best regards, Allan

By Chris2626 (***)

Date 06-19-2012 02:33

Dave, Allan Thanks for the tips. Allan I have seen this method on youtube where someone will weld extra metal onto the stud and building it up so they can grab it with vise grips, this maybe the best way to remove them because you're also adding heat at the same time.

The motor has a anode/fin although not sure if it is really a anode or just an aluminum fin really.

Dave I like your idea of going with plastic washers under the stainless washers, I'll remember this for sure when assembling it.

By Chris2626 (***)

Date 06-27-2012 04:12 Edited 06-27-2012 04:16

I got a piece of 5052 aluminum I went with 3/16 thick and was able to get someone near by the brake the sides into a channel but have run now into another speed bump.
I tried holding this piece up to the boat and was hoping I was only a 1/4 of an inch off, I must have had to many beers last time I measured it LOL but looks like I maybe a 1/2 an inch off.
I'm gonna weld this plate to three chimes on the boat the two chimes on each side of the keel is a little higher up and i figured I'd have to shim it some but dang it I didn't think I'd have to go 1/2 an inch. Guess I'll be having to do some ghetto engineering here, oh well guess thats what fabricating and going faster is all about.

You think I can buy like maybe 1/2x1/2 inch square tubing or stock in 5052?