How much pressure does a pressure washer need?

[Robert Wilson]

Well, since my water system operates on a foot pump, I don't much fancy trying to keep up with a pressure washer!
(And, with this being winter in Scotland, the fresh water system is long since drained dry).
Looks like a trailer with a big water container in it is the way to go.

On the seawater idea- I was told that it was essential to wash down with fresh water before applying antifoul, presumably something to do with salt residues stopping the paint from adhering properly?

Oi, mister - you are going to spoil it for us now, saying things like that........
And if it doesn't make it rain for the whole of 2013 in Noah-esque proportions, then we'll be inundated by soggy-southerners coming up here to dry out and taking all our lovely quiet anchorages and harbours.

All that guff aside, I'm interested to here about salt-water being a problem with A/F adherence. Anybody any definitive answers on this, please?

 

[dleroc]

I have a Hoselock PW and it definately does not suck.
Luckily my brother has an old one made by Champion and this works fine when stuck in a bucket of water.

 

[Amulet]

For my very small Kärcher it says in the spec - not to hand - how much head it needs, all I can remember was that it does need some positive pressure but it was remarkably low. I had a problem with it and thought it was lack of head. Turned out it was a airlock. I called them up and a very helpful women explained in German words of five syllables how to sort it out. No problem since then.

Volume of water was a problem. If I fit my hose to it with one of the autoshutoff type hose connectors it can't deliver enough water. With a straight-through it can.

My cheapo one from screwfix fell to bits, and the Kärcher is generation two for me - though it was bought at Homebase!

 

[NormanS]

Oi, mister - you are going to spoil it for us now, saying things like that........
And if it doesn't make it rain for the whole of 2013 in Noah-esque proportions, then we'll be inundated by soggy-southerners coming up here to dry out and taking all our lovely quiet anchorages and harbours.

All that guff aside, I'm interested to here about salt-water being a problem with A/F adherence. Anybody any definitive answers on this, please?

My previous boat was always antifouled between tides. I can tell you that a 60ft fishing boat has a big bottom. Where we did it latterly, there was a fresh water hose. Previously there was none. After washing down with fresh, it tended to dry off slightly quicker, but didn't seem to make any noticeable difference to the paint or adherence.
Have now seen the light, and have a much smaller boat, winter ashore, and antifoul at leisure.

 

[lw395]

Some antifoul is quite porous, so if you wash off with salt water all the time, it will end up full of salt, this might then draw in a lot of water by osmosis?
It's not hard to wash down with a sponge and bucket of fresh after using salt water to shift the slime.

 

[Robert Wilson]

Some antifoul is quite porous, so if you wash off with salt water all the time, it will end up full of salt, this might then draw in a lot of water by osmosis?
It's not hard to wash down with a sponge and bucket of fresh after using salt water to shift the slime.

Useful comment, thanks. Fortunately I shall be alongside the village quay this season for "unter der boaten verk", and it has a tap with a big hose for the fishing boats etc.

Thanks NormanS: You have just coined a new phrase for one of those ladies who you hope never sit beside you in the plane, train, bus, theatre etc etc. "A fishing boat?" or "A sixty footer".