what is acceptable pitting

[lu n russ]

what is acceptable pitting on a nearly 30 year old boat base plate

Edited November 13, 2009 by lu n russ

[Nickhlx]

what is acceptable pitting on a nearly 30 year old boat base plate

 

 

Umm... nice pitting that's not too bad ?...

 

Seriously... I would say not leaving less than about 3mm thickness... some hulls did not start off much thicker than this when new, and even this pitted area will be left with thicker material around it, so structurally still strong. Many might say thinner was still acceptable.

 

Nick

[lu n russ]

Umm... nice pitting that's not too bad ?...

 

Seriously... I would say not leaving less than about 3mm thickness... some hulls did not start off much thicker than this when new, and even this pitted area will be left with thicker material around it, so structurally still strong. Many might say thinner was still acceptable.

 

Nick

good to know that is still leaving 4.3 minimum

[Nickhlx]

good to know that is still leaving 4.3 minimum

 

I wouldn't worry - if the minimum is 4.3, then all around it is thicker and possibly thicker than plenty of other boats !

 

Nick

[PhilR]

what is acceptable pitting on a nearly 30 year old boat base plate

 

I assume your boat bas built about 1980 and is all original steelwork?

 

Do you know who the builder was? There was some great quality steel used at that time ....................

 

Have you had any ultrasound readings done on the base plate? and how deep do you estimate the pitting?

[blackrose]

I wouldn't worry - if the minimum is 4.3, then all around it is thicker and possibly thicker than plenty of other boats !

 

Nick

 

On the other hand it doesn't really matter how thick the surrounding area is. One could argue that a hull is only as thick as its thinnest point.

 

If the boat is out of the water it might be a good idea to fill the pits with weld.

Edited November 14, 2009 by blackrose

[lu n russ]

I assume your boat bas built about 1980 and is all original steelwork?

 

Do you know who the builder was? There was some great quality steel used at that time ....................

 

Have you had any ultrasound readings done on the base plate? and how deep do you estimate the pitting?

 

pitting on baseplate is up to 1.2 mm and 0.5 on sides and at its thinnest the base plaste is 5.6mm. builder is unkhown

 

On the other hand it doesn't really matter how thick the surrounding area is. One could argue that a hull is only as thick as its thinnest point.

 

If the boat is out of the water it might be a good idea to fill the pits with weld.

pitting is quite widespread would filling the pitting be standard practice

Edited November 14, 2009 by lu n russ

[Timleech]

pitting is quite widespread would filling the pitting be standard practice

 

You could spend forever if you start trying to fill all the pitting.

Yes to welding them up if there are a few really bad spots. Watch out for burning off the paint on the back, if the inside still has a useful paint film and you can gain access it'll be worth trying to touch it up where you've welded.

 

Tim

[blackrose]

pitting on baseplate is up to 1.2 mm and 0.5 on sides and at its thinnest the base plaste is 5.6mm. builder is unkhown

 

pitting is quite widespread would filling the pitting be standard practice

 

It doesn't sound too bad.

 

Are you on shore power?

 

If the boat has been regularly blacked and the pitting still seems to have happened fairly quickly, then it could be due to galvanic corrosion.

 

Have a look at the various galvanic isolator/isolation transformer threads. (This also assumes your mains electrical system is hull/earth bonded)

 

Edit: it also assumes you don't already have some form of isolation.

Edited November 15, 2009 by blackrose

[Theo]

(This also assumes your mains electrical system is hull/earth bonded)

 

 

If it's not then get it sorted PDQ.

 

Nick

 

Moving this to Boat Building and Maintenance.

 

N