Aqualu aluminum tub crack--

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vtcruiser60

vtcruiser60

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I purchased a NOS Aqualu tub about a month back from a guy in NH. It has not been installed on any vehicle. I found a crack in the door sill and am still scratching my head as to the cause. Take a look at the pictures. The crack runs between the sill and the bead. I suspect that the weld puddle was angled insufficiently into the sill, and the crack emerged due to internal pressure on the weld. What caused the crack on this new tub? The cracked area is in the passenger side. At the rear of the sill there is a hole that is replicated on the drivers side. I think this was part of Aqualu design. However, I do not see any drain holes in the bottom of the sill. I think that water may have pooled in this sill, froze, expanded and cracked the sill. This is my best theory so far. I am tempted to just drill out the crack at the ends (stress relief) and lay in a bead of JB weld. Tooling up my mig to weld aluminum is costly, and I am just not that good.

Thoughts on the cause of this crack and possible repairs?


***UPDATE--Hey folks...though this was not installed on a rig before mine, for all intensive purposes it is used. Unless Aqualu has some sort of lifetime warranty that travels with their parts (which I doubt) I don't see how this is a vendor issue. I am seeking your thoughts on what may have caused it and suggestions for repair. *****
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that looks like it was hit there moving the tub around at some point in its life. crack looks to have started at the weld booger on the right side of the second pic, and worked its way left.

poor penetration on the welds. could have been wrong angle, cleanliness or running the bead too fast or without enough heat.
 
There is a reason that the drift boat fisherman around here dont use aluminum boat trailers.
They end up looking like that after a few hundred trips up the bumpy dirt roads to the river put ins.
I would say it took a hit in shipping or sitting around.
I would find a fella with a tig to zap that with if I were you.
 
cruiserbrett said:
that looks like it was hit there moving the tub around at some point in its life. crack looks to have started at the weld booger on the right side of the second pic, and worked its way left.

poor penetration on the welds. could have been wrong angle, cleanliness or running the bead too fast or without enough heat.
Click to expand...

I hear you...but if there was an impact, I suspect it would show on the outside of the sill. There is no marring of any kind that looks like a side impact occurred.
 
I have seen the same problems with the 3 tubs I installed in the late '90s. I would have thought they fixed the problem. Do you have the date of mfr. on the tub?
 
when i got my aqualu tub a friend told me to drill drain holes in the bottom of the door frame posts because water gets in there and freezes and expands.. i can't completely tell by those pics.. but any chance that is what happened??
 
first pic ... looks like a crater crack at the end of the weld.. often if the crater is not filled in there will be a crack from the stress of the weld.. and in turn like you said might have water in it and froze .. i have seen this with tubing.....
look up hot cracking on aluminum...

second weld is probably do to the weld being to hot and causing toe cracks along the outer edge of the aluminum... aluminum shrinks by like 7percent ... causing stress on the weld

if there are any aluminum boat building places in your area.. they might be able to help you ...
 
That is nasty , I would get it welded , forget about the jb fix.
Did you discuss that with the vendor?
 
I remember reading once about hot cracking and filler metal choice. Here is a link to some additional information: ARC - Superior Welding Techniques

Since we live near a huge lake, there are loads of aluminum fabricators here working on docks and boats. I'll try to reach out to them and see if someone can lay down a new bead for me.

I'll also reach out to Aqualu to see what they recommend.

Several folks mentioned hearing about this type of crack before. This was news to me and perhaps is indicative of earlier versions of their tubs. If this is due to water pooling and freezing, then I suspect many folks would want to be looking into drain holes of some kind.
 
yes.. just a hole drilled at the bottom side of each door channel will prevent this.. as this is the only place on the tub where water can get inside and collect.


i got my tub like 7 years ago and i had to drill drain holes.. i wonder if aqualu is hip to the problem now and is doing this in production.. if not they should.. anyone with a new aluminum tub out here??
 
All Aqualu tubs I've installed over the last couple of years have had drain holes... they could become plugged being so small tho.....
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There is this stuff called aluma-lo (spelling is off I'm sure) you can use a propane torch or map gas torch and fix aluminum. I've used it a little and it's ok at best. I think I'd do that before I used JB-weld but a good welder can fix that with no problem should you want to spend a little more money. I would think the tub is worth that! Wish I could find a nice one cheap!
 
I have been in touch with Aqualu as well. They are kind to answer my questions and concerns, especially since this was not a direct purchase from them. It is their design however.

It appears that drain holes are in order. Aqualu has seen this type of cracking before. I suspect my crack was due to ice expansion in the sill. It is possible that pooling water in the gas tank area could have overlapped the sill and filled it shortly before an early fall freeze. Aqualu reported that drilling drain holes will not result in any structural problems to the sill area. I am going to do this after I get the crack repaired.

Water can accumulate in the sill for a variety of reasons and thus for folks with older (?) tubs, you may want to drill drain holes as well. I imagine that any substantial water crossing would fill the sill. I suspect a torrential downpour might pass a bit of water into the sill, but likely not enough to fill and freeze. If the tub is left outside before installation, tipped in a manner that will fill the sill, it may trap water.
 
Just a quick update...I finally got this tub to a welding shop this week. I ground down the original weld bead and drilled out the ends of the crack as a stop gap. I am heading out tomorrow to go pick it up......

The bill for a 15 inch aluminum bead.......$41.25...................ouch.
 
related question...

I have a second hand aluminum tub that has he same problem. The door sill clearly filled with water and froze over and over for many years while sitting outside. On mine, the outside surface of the tub is not flat, because the sill is bulged out at the top. Did you have this problem and if so, what did you do to smash it back flat? I have tried a vise and various clamps with no luck. Thanks!
 
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