I picked up an old trailer from Ebay and thought with a bit of heat, penetrating oil and a 6lb hammer i'd be able to free the screw clamps that loosen to allow free movement of the roller stems which had slightly rusted and had a coat of pain brushed over. I have 6 to sort and can't get a mm of movement my metalworking skills being poor.

I'm looking for one of two things. Any tricks of the trade................... or what do you call somebody who offers a mobile service repairing farm machinery etc.,? I've looked up metalworkers and welders come up, steel fabricators and sheet metal workers comes up etc.,

hwlp!

Lots of heat and a bigger hammer Heat,penetrating oil,heat,penetrating oil.I have also found using plumbers freezing spray works with heat, http://www.screwfix.com/p/pipe-freezing-kit-220ml/13369# This stuff.Heat 'till nearly red,then spray it on.The sudden shock can break the rust seal.This stuff will also work,use the can upside down.http://office.needa.ie/durable-powercle ... 7Qod_9EPAw ,and don't forget to get a bucket of patience as well

Many thanks HAC...

I think I might have an answer. I'm going to try and take the whole units off (two bolts) and chuck them at an engineering company to sort

Depending on what boat is going on the trailer you might want to consider bunks instead of rolllers. Rollers can be very damaging to boats - especially wooden boats, bunks are much kinder to the boat.

Picking these up this week from a local blacksmith/metalworker... I don't like to rush things

Before I finally put the trailer good use I aim to bosh it over with a lick of paint.

I'd normally reach for the Hammerite but a couple of stories online suggest it's not great for trailers so any suggestions?

If you are serious about the trailer then it needs to be blast cleaned, hot zinc spray coated, primed then a good quality enamel paint.
Will cost a bit but it won't rust.

To be honest I bought a bit of a pig and have had to put 4 new wheels, tyres, mudguards and a new coupling on it, am paying £40 to free the rollers and have new turnkeys made with more expense to come, broke down on the M25 when bringing it home and had to pay the AA £280 to get home so it's getting a lick of paint

Seriously. Appreciate what you are saying and will follow your advice in due course but the intention is to keep any rust at bay for now.