Reinforcing the uxter plate

[Murflynn]

needs a good coat of bright white hammerite . easy to do on a widebeam.

 

 

reminds me of a dirty Dutch workboat I visited. The engine room was spotless, the skipper required visitors to remove their boots and don the carpet slippers provided for the purpose. He was right pissed off when I pointed out a weep from a joint in a hydraulic line.

Edited May 1, 2015 by Murflynn

[blackrose]

Looks fairly solid to me. Looks like the flange at the top of the hatch may even brace into the tank?

 

Daniel

 

Yes it does.

[blackrose]

needs a good coat of bright white hammerite . easy to do on a widebeam.

 

 

I bought a couple of discounted 2.5 litre tins of Hammerite to do the job for a fiver each, but the only light colour they had was nice shade of lavender!

 

I don't think it really matters what colour you have under the deckboards as long as it's light so you can see what you're doing down there.

 

I painted the new skin tank to stop it rusting when that was welded in a few years ago. It looks blue in this photo.

 

[Murflynn]

looking good.

[DHutch]

 

Yes it does.

No issues the, in my mind.

 

I bought a couple of discounted 2.5 litre tins of Hammerite to do the job for a fiver each, but the only light colour they had was nice shade of lavender!

 

I don't think it really matters what colour you have under the deckboards as long as it's light so you can see what you're doing down there.

 

I painted the new skin tank to stop it rusting when that was welded in a few years ago. It looks blue in this photo.

 

 

Looks top dog, nice colour. Hammerite smooth spray paint is naff, but while I have only used the old-school hammered effect I am told it goes on well. My current 'paint of the year' for going on is Blackfriar QD 90.

 

 

Daniel

[blackrose]

Had the welding done today. I took your advice Daniel and didn't have the long piece of angle welded in. I also didn't bother with the short sections closest to the cabin bulkhead.

 

Port side: 3 lengths of 2" angle.

 

The uxter plate was sagging so badly the welder had to put in little feet made from 1" angle to bridge the gap. I didn't realise it was that bad until we offered up the straight lengths of angle. It's probably not welded in as many places as I'd ideally like, but hopefully it's enough to stiffen it up a bit.

 

 

 

Starboard side: 3 lengths of 2" angle + 1 length running perpendicular in front of the battery box to stiffen that area.

 

 

Now I've just got to scurf out all the rust and repaint it!

 

By the way, I don't suppose anyone wants to come and tidy up my battery cables and balance the batteries. I'll pay.

Edited May 10, 2015 by blackrose

[Murflynn]

The welder could/should have used appropriate clamps to bring the plate and the angle strip together, but at least you won't have a drainage problem.

 

I would put the battery box on top of the angles so it can be slid out for maintenance - you will need to lift it and slide in a wider base board to do that. Then a couple of through bolts to provide restraint for BSS compliance.

[blackrose]

The welder could/should have used appropriate clamps to bring the plate and the angle strip together, but at least you won't have a drainage problem.

 

I would put the battery box on top of the angles so it can be slid out for maintenance - you will need to lift it and slide in a wider base board to do that. Then a couple of through bolts to provide restraint for BSS compliance.

 

How could clamps have been used to bring the plate and angle together? The boat is in the water at the moment, but I think you'd need huge clamps to shift it whether in or out the water. I've tried to push the plate up from underneath when the boat was out of the water but it doesn't move - not unless a wave rolls underneath and even then it's only flexing a bit. The bow in the uxter is just the shape it was built.

 

I'll leave the battery box where it is. If I need to move it to paint underneath, the batteries will have to come out anyway and then I can just lift the box out.

Edited May 10, 2015 by blackrose

[Timleech]

 

How could clamps have been used to bring the plate and angle together? The boat is in the water at the moment, but I think you'd need huge clamps to shift it whether in or out the water. I've tried to push the plate up from underneath when the boat was out of the water but it doesn't move - not unless a wave rolls underneath and even then it's only flexing a bit. The bow in the uxter is just the shape it was built.

 

 

 

You use a scrap bit of plate as a bridge across the angle, welded to the uxter plate either side, and then a steel wedge between bridge and angle. May have been a mixed blessing in your case, because the angle and plate will each deform to meet the other & you will still have a (reduced) hollowness to the plate which may collect water.

 

Tim

[blackrose]

Ok, but this is 6mm plate so I think you'd need some serious forces to shift the plate back to flat. I'd rather leave it as it is.

 

I'm not really concerned about the profile of the uxter plate, I just want to increase stiffness. A slightly convex shape on the underside is fine with me.

Edited May 10, 2015 by blackrose

[Timleech]

Ok, but this is 6mm plate so I think you'd need a big clamp to shift the plate into shape - in a boatyard yes, but probably not the sort of thing your average mobile welder carries.

 

Also I'm not really concerned about the profile of the uxter plate, I just want to increase stiffness. A slightly convex shape on the underside is fine with me.

 

No clamp needed, just a wedge. Standard kit.

Main thing is that you are happy, I was simply trying to describe how it could be done if desired.

 

 

Tim

[blackrose]

 

No clamp needed, just a wedge. Standard kit.

Main thing is that you are happy, I was simply trying to describe how it could be done if desired.

 

 

Tim

 

Yes, sorry I misunderstood at first and just edited my post.

 

Do you think it will be stiff enough now? Are there enough feet?

[gazza]

Aa mentioned, its a shame the fabby didn't use strongbacks and wedges to pull that together, 6mm plate takes less persuading than you'd think.

 

They don't take long to knock up.

 

But, its likely to be stiffer than without the braces so not the end of then world!

[ditchcrawler]

 

I bought a couple of discounted 2.5 litre tins of Hammerite to do the job for a fiver each, but the only light colour they had was nice shade of lavender!

 

I don't think it really matters what colour you have under the deckboards as long as it's light so you can see what you're doing down there.

 

I painted the new skin tank to stop it rusting when that was welded in a few years ago. It looks blue in this photo.

 

I see they didn't use angle and only flat as braces

[blackrose]

Aa mentioned, its a shame the fabby didn't use strongbacks and wedges to pull that together, 6mm plate takes less persuading than you'd think.

 

They don't take long to knock up.

 

But, its likely to be stiffer than without the braces so not the end of then world!

To be honest, even if I'd have thought of it I'm not sure I'd have wanted him start bending the uxter plates. Who knows what sort of stresses that would put on the original welds, plus I've got a brand new bank of batteries sitting on the uxter that really don't need to be shaken up with hammer blows.

 

The shape of the uxter isn't a problem for me, as long as its adequately braced.

I see they didn't use angle and only flat as braces

Yes, that was my idea as its only a 3mm wall thickness skin tank. I was worried about it blowing out when it gets hot and pressurised. It works fine.

[gazza]

Fair comment about the batteries getting a vibromassage!

 

Any welded structure will have a fair amount of locked in stress. You won't made any detrimental changes to it. We are, after all talking about a large mild steel tub, not an intricate alloy steel fabrication

[Mutts]

 

Just think of the fun building gert big heavy riveted structures if Oscar Kjellberg hadn't perfected the covered electrode.

 

You would have burly men questioning your parentage to answer to instead

 

Mechanical engineers make the world go round, but us welding engineers stop it dropping on yer bonce

Is there such a thing as a "welding engineer"? Thought they were called "coded welders"

[Murflynn]

again we see a confusion between an engineer (who is well versed in design, theory, new developments, interpreting codes of practice and ISOs) and a skilled tradesman or technician who makes it happen in practice, according to the welding engineer's specification and to the best standards.

[blackrose]

Aa mentioned, its a shame the fabby didn't use strongbacks and wedges to pull that together, 6mm plate takes less persuading than you'd think.

 

The thing I don't understand is if the uxter plate comes up by half an inch so it's flat, then it's got to get slightly longer. Where does that additional length go if its already welded around the edges? I certainly wouldn't want the sides of the boat splaying out.

Edited May 11, 2015 by blackrose

[Paul C]

The thing I don't understand is if the uxter plate comes up by half an inch so it's flat, then it's got to get slightly longer. Where does that additional length go if its already welded around the edges? I certainly wouldn't want the sides of the boat splaying out.

 

It would have been (should have been) flat when built.....so the question is, when it sagged, did it pull the sides in?

[gazza]

The thing I don't understand is if the uxter plate comes up by half an inch so it's flat, then it's got to get slightly longer. Where does that additional length go if its already welded around the edges? I certainly wouldn't want the sides of the boat splaying out.

 

It would pull up making the uxter plate out of shape, all the strength is where it meets the hull side, it is highly unlikely it would splay the sides of the hull. you would end up with a rippled uxter plate but nothing worse.

 

You are over thinking it a bit

 

Its done now, so I wouldnt worry too much about the job you've had done, it will have put some more strength in to that large unbraced plate, maybe not as much as if thad been pulled tight to, but, as said before, its not really going to make a massive difference.

 

It does kind of highlight why I could never have a steel boat built for me by someone else! Thankfully I have neither the time, money, space or desire to go down the route of building one myself

Is there such a thing as a "welding engineer"? Thought they were called "coded welders"

 

 

again we see a confusion between an engineer (who is well versed in design, theory, new developments, interpreting codes of practice and ISOs) and a skilled tradesman or technician who makes it happen in practice, according to the welding engineer's specification and to the best standards.

 

Well put Murflynn.

 

Dont forget though, all of us connected with the welding industry are thickos.....

[blackrose]

 

It would have been (should have been) flat when built.....so the question is, when it sagged, did it pull the sides in?

I don't think the uxter plates were flat when it was built. They've always been like that. I used the word "sagged" earlier, but actually that's how it was built. The sides haven't been pulled in.

 

I don't really think uxter plates need to be completely flat for any reason. If they curve so much the better in my opinion - as long they don't flex. If you look at other boats, a (proper) swim on a non-narrowboat design like a Dutch barge is curved at every point.

Edited May 11, 2015 by blackrose

[blackrose]

 

It does kind of highlight why I could never have a steel boat built for me by someone else! Thankfully I have neither the time, money, space or desire to go down the route of building one myself

 

So either you have a GRP (or possibly an aluminium) boat, or no boat at all?

[gazza]

Own a GRP, done far too much on steel boats, its like a bloody busmans holiday!

 

I also have a 1 year old and a demanding job, along with mum who is a nurse that works nights/weekends so the chance of finding the time and money to do something like that wont be likely for some time

[Murflynn]

oh dear, Mike, you are definitely overthinking.

 

The 6mm plate was flat but when LB fabricated the boat they rested a wide piece of 6mm plate on the vertical swim plates, welded it into place and then flame cut it on at least the curved side. Like all pieces of thin plate it distorted under gravity and the heat produced during welding & cutting. The additional width that you are worried about probably amounts to less than 1mm (I could calculate it but it is insignificant). Bracing it so it was flat would splay the sides less than that amount, because the steel would partly take it up in compression. Don't worry about built-in stresses in the steel - it is a flexible material in the thicknesses we use on boats and would do no harm. The boat is full of built in stresses anyway.

 

Traditional Dutch 'barges' were built of formed plates (deliberately curved) which is a different thing altogether.

 

Don't worry about it.