# Preventing rattling



## fishjunky (Jul 20, 2015)

I'm starting to cut my 1" square tubing to fit the ribs and I started thinking about the possibility of aluminum on aluminum rattling. I'm going to rivet it down, but do I need to do anything else? Was thinking about a piece of rubber gasket material or maybe a dob of silicone?


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## Skiffing (Jul 20, 2015)

No gasket or silicone.

Two rivets each connection. 

What sizes are you using? Make sure you use the proper drill size [3/16 rivet does NOT take 3/16 bit] and the rivet grip range is correct.


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## fishjunky (Jul 20, 2015)

Planning on 3/16" rivets. I won't be able to get two rivets at each connection.


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## Skiffing (Jul 20, 2015)

If you're decking with wood - use two even if you have to peel back one leg of the tubing to make a 2nd connection.

If you're decking w/ aluminum you can apply rivets in a "T" pattern within an inch or so of the connection and they will take some of the stress.

Where decking is not going to be fastened - like rib to tubing - IMO you need 2 rivets / connection.

Just my opinion.


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## fishjunky (Jul 20, 2015)

I'm not 100% sure what you mean by peel back the metal.

The spot I'm talking about is where the tubing meets the small rounded ribs at a steep angle so there is only a small point of contact. 

It will be decked with 1/16" aluminum with blue board insulation underneath.


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## Skiffing (Jul 20, 2015)

Pictures of what you want to do would help.

Also please complete your profile so we know where you hail from.


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## fishjunky (Jul 21, 2015)

The silver one is not above a rib. That's where the front edge back deck will be.


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## Skiffing (Jul 21, 2015)

I see what you're doing now.

The hull has a fair amount of flex - by design. Without a rigid connection between the tubing & rib it will loosen. If you're also going to put some holes below the water line..... they may also loosen and leak.

If the ribs have enough vertical surface you could use a gusset on each side. That would work - but minimum of 2 rivets per connection - so that would be 4 per gusset - minimum.

By example I installed a bench seat [see my build] and thought I'd cheat and use 1/8" rivets for the seat to angle connection. I figured every two inches would work. For the angle to deck / stringer I used 3/16" but got tired of snapping them off.

Didn't work. First good chop I was in looked down and saw a bunch of rivet heads on the deck :roll: 







Welding would not be very expensive if the welder does not have to do the prep........


I removed the rest and installed 3/16 every 2". No more problems.

There are other members here who have much more experience than I have riveting aluminum - hopefully they'll chime in.

PS - drill some 1/8" holes in the bottom of the tubing for weep holes.


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## onthewater102 (Jul 21, 2015)

Square tubing is going to be a waste for you the way you're using it there - looks like you've already got your material, but if not angle would work the same and cost considerably less. It's easier to support with a vertical leg too. Those rounded ribs aren't going to give you much contact area, but if you're crafty you should be able to get 2 rivets into each junction, but I don't think you'll be using solid rivets

If you're using all aluminum rivets I'd stick to 3/16" as Skiffing said - I too had bad experiences early on with 1/8" - though I'm not running in salt water so I just went to 3/16" stainless rivets to be sure nothing moves. Get the rivets with steel mandrels...you forearms will hate me for suggesting it, but they pull much tighter. Guessing by your lack of paint in some areas vs others that you took out the seats. Might also when you're done with the floor add some cross-member supports from the floor ribs up to the gunwales.


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## Skiffing (Jul 21, 2015)

^^^

Good catch on the seats. They were intended as structural members.


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## onthewater102 (Jul 21, 2015)

Especially on a boat with ribs designed the way those are where they don't extend up the sides of the boat. Those seats were important to keeping it all from flexing.


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## fishjunky (Jul 21, 2015)

I won't be able to get a rivet in the side of the rib ... Too short. 

I guess I could maybe rivet a short section of tubing to the rib lower down toward the centerline of the hull and then use a piece of flat stock to connect the cross member to the short piece of tubing? That should be roughly the same result as going straight to the rib. 

I have a section of ladder running fore to aft that ties the hull and cross members together. I will try to get a picture up shortly.


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## fishjunky (Jul 21, 2015)

I don't have all the cross members cut yet but you get the idea. I have the ladder notched to receive the 1" tubing. The ladder will be attached to the ribs as well. The angle will be used to stiffen the gunnels.


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## fishjunky (Jul 21, 2015)

Oh and I got the tubing for a dollar a pound so I'm sticking with it. 


Not sure what it was designed for.


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## Skiffing (Jul 21, 2015)

Any number of fabrications - maybe window frames.

The plot thickens.............

You're a carpenter aren't you?

He, hee 8) 

With that ladder in there you don't really care about rattles!

If the ladder flanges rest solidly on the ribs you can use them as a fastening points - but you'll need more than 3/16. Since you cut through the upper chord of the ladder for the tubing it should bend enough to lay down on the ribs?

If you fasten the deck well at that intersection you probably won't have a problem.

The ladder rungs are useless if you can do that - you can get rid of them. The deck sheathing will provide enough lateral support to the new "stringers" so they will be solid vertically.

Where your tubing extends to the hull I do not see any way to fasten to ribs without welding. Cantilever - leaving them loose will chew everything up and one rivet will pull loose.


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## fishjunky (Jul 21, 2015)

I don't know if it was divine intervention helping me find that ladder, but it fits darn near perfectly touching each rib all the way up. That's why I felt comfortable cutting the top fold of the ladder, because it's a direct transfer of weight down to the ribs. 

So you are saying any type of cantilever will cause movement and metal running and loss of metal?


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## fishjunky (Jul 21, 2015)

Why would the 3/16 rivets not work for connecting the ladder to the ribs? Seems plenty sturdy for holding it in place to me.


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## Skiffing (Jul 21, 2015)

Divine? Perhaps :LOL2: 

Time to ask:

What is the boat?
What power does it have?

I noticed you didn't admit to being a carpenter. Don't know if that's good or bad .....

Look at it this way - once you have your deck fastened on - would it be a REAL PITA to refasten your stringers?

Answer - Probably - unless you enjoy doing things more than once.......... So get it right 1st time.

I don't see any way to get the tubing fastened to ribs without welding. Leaving them loose will chew things up. If things need to be welded - prep everything - ladder stringers and all and let a welder do it. If it is prepped properly there is less than 1 hour welding time. In N.C. - what's that? $100. You're done.

Rivet the 1/16" deck in and have fun.

If you're bent on mechanically fastening ladder stringers to ribs my "guess" would be RIVNUTS. But you'll need special tools and precise installation.

Johnny - where the heck are you? [oh ya - fishing]


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## fishjunky (Jul 21, 2015)

Well I used to be a carpenter, now I just do estimating. I still do woodworking as a hobby, but this metal working is new to me.

Boat is Sears Gamefisher 13'8", 1982 model I think, powered by a four stroke 20 hp Honda.

Fair enough about the welding... I'll check into it, It can't take over an hour once they fire up the welder. Should I be concerned about them kicking a piece of tubing and knocking it out of alignment though? Duct tape stuff in place?


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## Djknyork (Jul 21, 2015)

I'm with skiff... You're going to have to get it welded in certain spots.


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## fishjunky (Jul 21, 2015)

What would I need to do to prep for welding?

I'm assuming wire wheel the paint and any corrosion. Anything else?


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## CedarRiverScooter (Jul 22, 2015)

Use a new stainless steel wire brush, that has not been used on steel. Otherwise you drive impurities into the aluminum. If it was me, i would use pop rivets or screws to jig all the pcs in, then take it to the welder.


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## Skiffing (Jul 22, 2015)

Correct - Brand new stainless steel brush - only use on aluminum. 

If tubing is anodized remove to bright aluminum at weld sites - all faces. Ribs - clean to bright aluminum

Aluminum oxide sand paper or sanding wheel

Acid wash 

Acetone cleaning

In that order

Prefit all pieces.

Welder will have to acid wash to remove oxidation that will form immediately after you finish your prep - but he has to do that to any aluminum he welds including brand new.


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## fishjunky (Jul 24, 2015)

I stopped into a local welding shop. They offer tig welding but recommended finding someone that can weld aluminum with a mig welder. 

Does this sound right?


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## Johnny (Jul 24, 2015)

I'm sure that in Fish's mind, all the pieces come together.
we are not there. we can not imagine his vision.
I see it now, 14' flat bottom Jon with a 20hp.
So I am just lurking to see how it all pans out LOL.

I can answer one question - - - 
the square metal tubing is called Balusters or Pickets for porches, decks and such.



available in the Big Box Stores. Another item of similar usefulness is the 
1.5" square tubing for pool enclosure screens. good for transoms.

now, as for the puzzle of the ladders, stringers, rivets, welding, yada yada yada
I just can't wrap my head around the big picture yet to offer any kind of direction.

Jus my Dos Centavos

oh, just for education - you can Google up *MIG* and *TIG* welding and see what it entails.





.


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## Johnny (Jul 24, 2015)

okay okay okay - - - Fish guy - - - 

put aside *ALL* the above information . . . cut all your pieces to fit the way you 
envision the final project. Don't rivet, screw, bolt, or weld anything. Just dry fit all your
pieces. Put it all together, cut the wood for your floor and just lay it on your frame
then ..... put in a few self taping screws to hold it all in place. 
Go put your boat in the water and run it around for awhile and take notes. 
Then come back to your shop.
remove the floor. Make whatever adjustments you deem necessary. 
THEN - if you need more help, everyone will be glad to pitch in their dos centavos.

In the meantime, everyone is making this simple project WAY harder and more
complex than it has to be.
it is a _BOAT_ !!! not the Space Shuttle !!!
good luck - have fun.


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## Skiffing (Jul 25, 2015)

fishjunky said:


> I stopped into a local welding shop. They offer tig welding but recommended finding someone that can weld aluminum with a mig welder.
> 
> Does this sound right?



Nope. Tig is preferred.


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## fishjunky (Jul 25, 2015)

Hmmm he said the tig would take a lot longer and would risk "bleed thru" because the hull is so thin. I guess tig is much hotter than mig?

Maybe he was just trying to find an excuse to not do the job because he didn't want to mess with it?


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## Skiffing (Jul 25, 2015)

They are both adjustable power and wire size. Tig has better penetration but is used in 1/8" aluminum all the time. Mig will also work.

Youd be welding to a rub - not the hull.


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## fishjunky (Jul 25, 2015)

It would be on the hull in a couple of places though.


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## richg99 (Jul 25, 2015)

Only time I tried to get a welder to work on my boat, I could tell he REALLY didn't want to be bothered. Try another welder.


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## fishjunky (Jul 28, 2015)

Still looking for a welder... Was researching tig vs mig on the web and ran across info on DIY aluminum brazing. Does anyone have any experience on muggy weld or HTS-2000 products?

https://youtu.be/RCrixbXz4rc
Starter kit (enough for my project) would be $65.


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## Johnny (Jul 28, 2015)

I am easily frustrated when I try something new and I don't 
get satisfactory results right away.
I bought a pack of those aluminum brazing rods 40 years ago
and still have them.
15 years ago, I watched my neighbor repair a small hole in his Jon Boat
only to watch the hull ripple and warp where the heat was not consistent.
$65 is a bit steep, IMO, try to find a few around locally to practice with.
The guys at the Trade Shows make it look so easy. Welding Coke cans together, etc.

They are on E-Bay much much cheaper. Less than $15 for a kit.

The technique is to have the substrate (the material to be welded) hotter than
the brazing rod. The base material must melt the brazing rod, not the torch.
there is a good margin between the melting temperature between the two.
The secret of the technique is to have the base metal melt the brazing rod.
Don't melt the brazing rod with the torch.


jus my Dos Centavos


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## onthewater102 (Jul 28, 2015)

I tried the HTS brazing rods...terrible results working with thin materials. The thin skin of the boat rolls and warps at the temperatures you need to get the brazing to work well. I had a bad experience with it trying to fix leaks on my 12' Sea Nymph where it really distorted the hell out of the floor and blew threw in places where I gave it too much heat.

Recently I tried it on 1/16" angle (thinner than the boat skin trying to get better at it) and I was able to make a rack for the front of my boat but I had the same problem where the 6063 alloy aluminum was melting at barely more temperature than the brazing rod took. I was eventually able to get it to work but there were a lot of failed pieces - you've only got one shot to get it right with the hull of your boat.

I did for s**ts & giggles try them on scraps of the 1"x1" 1/8"thickness angle I used for my deck structure and it worked well on that.

I'm picking up some 100% argon shield gas so I can try my MIG welder on aluminum, though I've heard mixed reviews about the quality of the weld MIG welding puts down on aluminum (not as good a penetration or as smooth a final weld as TIG).

This seems to be the best source of info I've found thus far on the subject:
https://www.mig-welding.co.uk/aluminium-welding.htm


TIG welding is the way to go - and worth the drive to find a shop that will TIG weld it for you.


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## fishjunky (Jul 28, 2015)

Fair enough. Thanks for the feedback. I'll keep looking for a pro or at least a semi pro welder.


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## Skiffing (Jul 28, 2015)

^^ A semi pro will work. Mig WILL work and is used all the time for this kind of work. So don't be put off by that. TIG is preferred - is all for a number of reasons - main reason is probably the weld is deeper and can be faired to the parent material and become invisible. With Mig you NEED to leave the bead - cause that's where the strength is.

Prep is key. If you do that well you can ge this done on the cheap. Maybe even save your ladder for another project :shock: :shock:


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## fishjunky (Aug 11, 2015)

Well I'm 0-for-3 on welding shops. No one wants to touch this project because the aluminum is so thin. 

I'm regretting starting this project at this point....

I've already got the ladder notched to fit the 1" square stock at most of the cross supports (one I did a piece of angle due to the cross piece falling right over a ladder rung). 

I wonder if I could replace the square tubing with 1" square white oak (rot resistant and on hand). 9 pieces shouldn't add that much weight in the scheme of the project. If I used the oak would it matter if the ends aren't connected to the hull? I could use small screws to secure the alum decking to the oak strips and then rivets where it falls over the ladder. I was planning on filling up all the void with blue board insulation except for a central channel.


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## Skiffing (Aug 11, 2015)

Give Modliin's welding inn Farmville a call.

https://www.facebook.com/ModlinsWelding


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## fishjunky (Aug 12, 2015)

Farmville is a long drive for me.


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## Skiffing (Aug 12, 2015)

They are marine welders.

I didn't say "go there" :? 

I suggested you call them.

It is likely they know every aluminum welder from there to Arkansas.

Plus - if they wouldn't be interested in doing to job for you - you know you have a problem.


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## perchjerker (Mar 3, 2016)

can I asked how this worked out?

read through the whole thread just to see it die.

thanks


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## fishjunky (Dec 8, 2016)

I wound up making a bracket a of 1/16" angle and riveting it down as close as possible, and then gooping down the loose end.


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