[ray mck]

In Homebase's at the weekend seen a 15 ltr backpack sprayer. £18 not sure if it's any good for hypo or anything.

[Smurf]

I take it at that price was a backpack hand pump sprayer?

Put it this way after experiencing chem burns from hypo I defo would not want that strapped on my back. They are cheap for a reason as are not meant to be used with aggressive chems so will start leaking and stop working altogether in no time at all.
If you are after a small pump up sprayer expect to pay a lot more that come with viton seals. Still using a strong mix of hypo will eventually kill those as well.

Can I ask what you want to use it for?

[Kev Martin]

Buy a Birchmeier or a Gloria with Viton Seals

[Smurf]

If you want something really cheap then this seems to be trending on bookfarce pages at the mo.
http://www.ebay.co.uk/itm/282055939662

How long the pump will last is another question though but might come in handy as a cheapo portable delivery system to say applying tfr, ubik, weak hypo mix etc to surfaces directly from a 20L container or bucket. You could do away with the cig plug altogether and buy a cheapo small battery and stick it all in a box if you wanted to make it fully portable.  Also could be used with a wfp too  by using a hozelock adapter on the pole hose if need be.

There are also some vids on bookfarce pages if interested.

[Smurf]

For general pressure washing use some prefer to use a downstream injector either fitted after the pump or at the end of a gun or lance to apply soap/chems which are also cheap to buy.  Mind the spray drift can be horrendous so this method is not ideal especially for spraying the likes of hypo on vertical surfaces like render house walls etc.