Surveyers Hammer

[BurnitBlue]

Many, probably all survey reports mention a hammer test to look for delamination. What type of hammer do they use. Steel, rubber, plastic or one of those hide bound things. Is it a special shape or will an ordinary light ball pane hammer suffice. It must be light enough to be able to tap away for a few hours.

I expect delamination will sound like a dull thud. Is it a usefull test?

Thanks.

 

[sarabande]

something treated to BS876 1995 would be best.

 

[chinita]

'one of those hide bound things.'

(hīd'bound')
adj.
Stubbornly prejudiced, narrow-minded, or inflexible.
Having abnormally dry, stiff skin that adheres closely to the underlying flesh. Used of domestic animals such as cattle.
Having the bark so contracted and unyielding as to hinder growth. Used of trees.

Another idiom?


'Is it a special shape or will an ordinary light ball pane hammer suffice.'

Do you mean Ball Pein?

I think you have been out of the country for too long!

Actually, yes it is a light Ball Pein Hammer. When you hit a delamination or a void in the resin the difference is very noticeable.

 

[Ex-SolentBoy]

'one of those hide bound things.'

(hīd'bound')
adj.
Stubbornly prejudiced, narrow-minded, or inflexible.
Having abnormally dry, stiff skin that adheres closely to the underlying flesh. Used of domestic animals such as cattle.
Having the bark so contracted and unyielding as to hinder growth. Used of trees.

Another idiom?


'Is it a special shape or will an ordinary light ball pane hammer suffice.'

Do you mean Ball Pein?


I think you have been out of the country for too long!

Actually, yes it is a light Ball Pein Hammer. When you hit a delamination or a void in the resin the difference is very noticeable.

I think you might be being a little picky.....

From a well known source

"A ball-peen (also spelled pein and pane[1]) hammer, also known as a blacksmith's, engineer's or machinist's hammer, is a type of peening hammer used in metalworking. It is distinguished from a point-peen hammer or chisel-peen hammer by having a hemispherical head. Though the process of peening has become rarer in metal fabrication, the ball-peen hammer remains useful for many tasks, such as striking punches and chisels."

 

[capnsensible]

Its forged from kryptonite and then sprinkled with oofle dust. How else do they justify a survey cost???

 

[Deleted member 36384]

According to the surveyors tool list in Surveying Yachts and Small Craft by Paul Stevens and his comments on the tools, he recommends a small panel pin type hammer for this exact job.

The surveyor when conducting a non destructive examination is only looking for a light, sharp, tap to make the dull but precise sound of a good hull. The de-laminated area will be obvious. Smacking the hull with a heavy hammer will not produce an easy to detect change in noise.

Think toffee hammer, not sledge hammer if you wish to tap out a tune with fine control.

 

[Seajet]

Things like pinhammers and indeed ball peins might be all right on wood, but if someone strolled up to my grp boat with a ball pein hammer, illuminated flashing 'surveyor' sign on his hat and gold braid epaulletes or not, they'd better make the first tap pretty light, or they'll be face down in the ambulance to A&E to have it removed...

 

[BurnitBlue]

Things like pinhammers and indeed ball peins might be all right on wood, but if someone strolled up to my grp boat with a ball pein hammer, illuminated flashing 'surveyor' sign on his hat and gold braid epaulletes or not, they'd better make the first tap pretty light, or they'll be face down in the ambulance to A&E to have it removed...

Thanks all so it is normal to use a small lightweight steel hammer. Lots of humour and the message got through that I won't be lynched if I make very very light taps which will also help in identifying the sound.

 

[paulstevens]

??

That's actually pretty insulting Seajet. It would be more constructive if you could read the full passage in my book as to how to do the job with finesse, and why particular types of hammer are suitable or not, then if you wish offer an alternative reasoned view on here preferably based on your years of experience.

This non destructive test is the most important and telling of any. If I could have just one tool conducting a survey it would be a light pin hammer. It isn't just about the sound, its about the degree of "bounce back" often experienced when delam is present.

Incidentally I do not wear gold braid, but I do have a rather fetching gold earring.

 

[Seajet]

Paulstevens,

Well you have just come out absolute bottom in a survey of my own I wasn't consciously conducting !

While BlueTwo ( 'Battle of Britain' ? ) proves he has a sense of humour, if you can't catch on to that i certainly wouldn't let you near my boat, hammer or otherwise !
I happen to come from an engineering background, and am well aware what can be achieved with a ball pein - our aerospace grade coppersmiths regularly produced miniature milk jugs made out of pennies.

I often use tapping on the hull myself - with a knuckle - to locate bulkheads for trestle positioning etc, but I do know what a LIGHT tap with a ball pein will do and am familiar with all sorts of NDT...

BTW Paul, been playing with boats since 1972, hammers about then too though only paid for it since 1978.

 

[boomerangben]

Seajet,

I am sure all surveyors are pretty gentle with their hammers. After all if they used their knuckles day in day out, they would have a pretty short career. I just wonder what all your fittings are made of if the gel coat on your boat is so fragile. Wooden winch handles? Rubber shackles? Silk anchor chain on a felt anchor? But I hear what you say and would wonder if the wooden handle of a hammer was just as effective at sniffing out de-laminations.

 

[Woodlouse]

Unfortunately for Seajet, any surveyor that doesn't use a hammer to check out the hull and deck is really not worth paying. If the hammer does damage then it's the boat that is the problem. If it can't take a tap from a hammer, how is it going to stand up to a wave?


What you do have to watch out for though is the surveyor that has a selection of hammers. And works his way up from a very little one to a very big one until a structural problem is found.

 

[SHUG]

The better equipped surveyors have a machine which measures the hardness or softness of the hull. The hammer is yesterday's technology.

 

[paulstevens]

The better equipped surveyors have a machine which measures the hardness or softness of the hull. The hammer is yesterday's technology.

No, it measures hardness and softness of gelcoat.

No use for detecting voids and delam.

Google Barcol

I've remembered why I stopped contributing to these forums years ago.

 

[paulstevens]

Paulstevens,

Well you have just come out absolute bottom in a survey of my own I wasn't consciously conducting !

While BlueTwo ( 'Battle of Britain' ? ) proves he has a sense of humour, if you can't catch on to that i certainly wouldn't let you near my boat, hammer or otherwise !
I happen to come from an engineering background, and am well aware what can be achieved with a ball pein - our aerospace grade coppersmiths regularly produced miniature milk jugs made out of pennies.

I often use tapping on the hull myself - with a knuckle - to locate bulkheads for trestle positioning etc, but I do know what a LIGHT tap with a ball pein will do and am familiar with all sorts of NDT...

BTW Paul, been playing with boats since 1972, hammers about then too though only paid for it since 1978.

Ridicule is not funny where I come from.

 

[Resolution]

No, it measures hardness and softness of gelcoat.

No use for detecting voids and delam.

Google Barcol

I've remembered why I stopped contributing to these forums years ago.

Don't give up on the forum - we need all the professional input we can get. And don't let Seajet needle you - with only 39 years sailing experience he still has some way to go to catch up with the average forumite!

 

[yacht surveyor]

That's actually pretty insulting Seajet. It would be more constructive if you could read the full passage in my book as to how to do the job with finesse, and why particular types of hammer are suitable or not, then if you wish offer an alternative reasoned view on here preferably based on your years of experience.

This non destructive test is the most important and telling of any. If I could have just one tool conducting a survey it would be a light pin hammer. It isn't just about the sound, its about the degree of "bounce back" often experienced when delam is present.

Incidentally I do not wear gold braid, but I do have a rather fetching gold earring.

Paul runs the only practical surveying course in the country. His knowledge and his ability to pass on his understanding of damaged yacht structures is greater than most people who are working with yachts.
Even boatyard staff who work with boats every day often ask stupid questions of surveyors.

When it comes to practical surveying, there are few who can pass on the knowledge in as good a way as he does.

Paul's course is the only course which is of a sufficiently high standard for the graduates to be recognised (if they apply) by the Yacht Designers and Surveyors Association.

 

[yacht surveyor]

The better equipped surveyors have a machine which measures the hardness or softness of the hull. The hammer is yesterday's technology.

The Barcol hardness tester only really tells you if the gelcoat has properly cured.
It does not reveal delaminations, or other defects.

The hammer is the principal tool for all surveyors.

 

[G Connor]

Sorry gents but using a hammer is hit and miss and not accurate .Use a hammer on most builds today and you would be kicked off the job. Thermography or Ultrasound are the tools to use.Sheerography for aerospace.http://http://intyachts.co.uk/thermalimaging.aspx

 

[G Connor]

You forgot to mention thermography ultrasound and sheerography