Crack in Aluminium

[ba229]

Sitting out in the boat last night i noticed my feet sitting in about 2cm of water. i bailed it and 2 hours later it was like it again.

Leak, i can hear you thinking.

Today i put the bung in and turned on the hose. Sure enough there is a small leak from a previously repaired crack.

This repair consists of a sealant of some sort and a bit of paint.

It appears to be from an incorrectly mounted battery but that is now fixed.

Now don't get me wrong i am not too worried about this crack but am seeking for advice.

I read the posts about get welding done but was thinking something a little easier.

What do you think about removing old sealant, stop drilling the crack so that it doesn't grow (drill small holes at either end of crack to reduce stresses), and then using a bog of some sort to fill the crack.

I thought i once saw a post where people were suggesting builders bog and that product called "nead it" or something like that.

Here are two photos and i hope you can add some advice on this topic.

Regards
Alex

[ba229]

And heres a close up. Note i haven't cleaned away the paint or old sealant yet.

Going fishing on Tuesday and will leave so that it doesn't leak worse.

When i filled the boat with water (only about 15% really) it was a drip every 30 seconds.

[Gorilla_in_Manila]

Alex,
Is that the correct position of the boat on the trailer? If so, I'd say its due to the weight of the motor, battery and boat banging up and down on the runner there. Might want to think about putting some new longer ones after the repair.
Not too sure about the repair, but I don't think much of that knead it stuff. If its the same stuff, i used it a bit plugging lures but seemed to stay a bit soft. Whatever you end up doing, I'd think about extending the runner to take the stress of that point, othewise it would just flex and crack again I'd think.
Shano's the boilermaker, see if you can give him a pm. My brother used to talk about this stuff he called liquid steel.

While you're at it, go have a look up at the roller up under the nose below where the fuel tank is sitting. On my boat, I screwed up and left an old rubber roller there, and the keel cut through it and then the boat started resting on the steel pin. Got cracks and stuff there I have to fix now, so I will be watching this space carefully. I'm going to then move the position of that roller, change it to a new type (neoprene is it?) and maybe add another one to share the load.

Good Luck,
Cheers
Jeff

[Big_Kev]

That crack has been caused by the incorrect trailer set up.
I would say you have to much weight on the rails.
The only way to fix it is to get it TIG welded by a pro.
Then be sure to correct the trailer.
Where are you and someone will recomend a good repairer.
Hope this helps Kev.
Well thats my qualified oppinion take it as you will.

[ba229]

I'm in newcastle so if anyone knows of a welder down this way let me know.


If so, I'd say its due to the weight of the motor, battery and boat banging up and down on the runner there. Might want to think about putting some new longer ones after the repair.

I'm not too sure i understand what you mean by longer rollers. Could you explain this further for me.

regards

[aido]

think he means the skids.
nasty crack where the skid ends.
i think you've got to dig the old putty and crap
out of the damaged area and clean it up.
green or red scotch brite is good at polishing the
area. when you can see what your dealing with, stop drilling the ends of the crack is the go.
maybe get someone with a gas torch and try sealing it up
with those you beaut techni2000 brazing rods. they work well
but cleanliness is the key, start polishing that alloy.

[krazyfisher]

not rollers but the skids on the side was what was meant. the rollers in the center need to take the weight the skids should just guide it and keep it in positions

[ba229]

The trailer is in it normal towing position.
Here is a photo of the rollers.

[ba229]

yeh sorry now i get it. skids/runners not rollers. sorry i didn't read the post correctly.

[ba229]

heres a picture of the skids. they do look a bit small. do they need to extend right to the transom? or just a bit further than they do now?

[ba229]

Another thought i have had is the strap that goes across the boat. this would be pulling the boat down onto those skids increasing the load they take. maybe if i slacken the strap off a bit. mind you it isn't real tight as it is.

[krazyfisher]

one thing to take note dont use techni2000 rods to repair the crack unless they have changed they used to have lead in them and a lot lead and aluminium dont mix well.
as for the skids the trailier looks abit small the trailier normally goes back to where your back roller is making it easier to put longer skids on but yes I would think you need longer skids

[Gorilla_in_Manila]

Alex,
Yeah, runners / skids - but you've sorted that.
Think I've got the same trailer as you and my skids are about twice as long as yours and tapered down a bit at each end.
Cheers
Jeff

[Big_Kev]

BA for sure after looking at those photos your skids are the root cause of the problem.
It will cast around $100 to repair the crack.
You will need to make the skids at least 1mtr long.
I have seen your type of trailer before and it can be done but you will need to go to the boat shop (a good sized one) and get some mounting hardware for the skid, it will need to be mounted at both ends, same mounts as at the end now.
Skids can be bought (poly) or hardwood will do (cheap)(fence timber).

The better part of the boat weight should be mounted along the keel when on the trailer,and the skids are for support only with only some weight.
TheAlley craft web site can provide some good tips.
It is best to tie the boat down at the transome from both sides to the center.(two straps)
The across the top is not worth a pinch of shit.
Go for a ride in the boat and you will see how much it will bounce on the trailer.
Hope this helps Cheers Kev.
We did warn you that it is a money pit LOL.

[Gorilla_in_Manila]

Alex,
Has that back roller been extended out a bit?
You seem to have a lot of boat behind the axle position.
How much weight is up front on the ball hitch?
Cheers
Jeff

[ba229]

lol the money doesn't worry and neither do making mods.

when i bought my last motorbike it ran like a sack of s*?t.

half the fun was making it just right and now i get on it and just ride.

nothing like have things to do i reckon. nothing worse than buying a toy that you can't tinker with and improve :-)

thanks for all of the advice guys. it's really great that i can post a photo about one issue and you guys get to the root of the problem. if you can think of anything else let me know.

p.s. i will be posting photos of the skid mods as they happen.

[GES]

These blokes have diagnosed the problem and offered the solution for you.
Here's just another point to remember, for later, about pressed alluminium boats ... don't pack the camping gear, the fishing gear, the wifes wardrobe and the budgies bath salts all in your boat if you are going away on holidays. Alluminium boats were never designed to act as a carry all. Cracks 'em real quick.

GES