How to straighten a bent P bracket?

[paulrossall]

I have a 14inch long P bracket that had a knock under previous pwnership and needs to be staightened. It is off the boat. One option is to bolt it to something solid and hit it with a sledge hammer. Is there a more precise way of sorting this? Where should I take it to get it put right? Location Nottinghamshire.

 

[bilbobaggins]

As learned on an RAF Instrument Fitters apprenticeship - "Don't force it! Use a bigger hammer...."

/forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif

 

[totopalm]

Before using the "Birmingham Screwdriver", what material
is the P bracket made of ie; is it steel/iron/brass/aluminiun
copper/spelter/pewter/wood/cardboard/compressedwood
or any other useful material, from which a P bracket can
be fashioned. This knowledge is extremely important

 

[paulrossall]

It is phosphbronze. I did wonder whether it would be better if it was heated whilst being bent.

 

[alb40]

My (slightly) bent rudder and P bracket were straightened by a local engineer.

A combination of 10 tonne press and careful use of heat returned them to servicable condition. Shafts didnt fair so well, had to have new ones. Lots of money!!!!

Dont allow idiots to put your boat in a dry dock without blocking it up as the tide goes out during a survey is the moral of the story /forums/images/graemlins/confused.gif

 

[vyv_cox]

Phosphor-bronze is not a common alloy to use for this purpose but if you are certain of your facts, then heating it will give no advantages but could cause problems. The ductility of a cast phos-bronze is reasonable (18% elongation) and of a wrought much higher. Cold working it to straighten would be quite acceptable.

Rather than whack it with a hammer it would be preferable to have an engineering company use a press to straighten it. It would not cost much, be much better controlled and eliminate the risk that hammering might cause.

 

[paulrossall]

Following your reply I have checked up on the p bracket and it is actually bronze. I suppose I should take it to a proper marine engineering business. The nearest to me is in Hull, a 130 mile round trip. They regularly straighten p brackets so they should know what they are doing. Thanks Paul

 

[vyv_cox]

Bronze is possibly one of the 'marine' bronzes which are actually brass with some added tin. The bronze will have equivalent mechanical properties to a 60/40 brass which is quite ductile. Bending it straight should not be a problem. Again, I would definitely not heat it.