Has anyone used a Rendergun for lime rendering?

[Inspector John]

Has anyone ever used or has knowledge on using a rendergun for lime rendering?
Also would you still put 2/3 coats of render on (leaving each coat to carbonise) or do the rendering all in one go?
Many Thanks

 

[Gervase]

Yes.
I did one house with a render gun and full-sized compressor, but wouldn't do it again.
To be honest, it's just as quick trowelling the render on if you've got reasonable trowelling skills - particularly when you taken into account the masking of window openings and doors, and laying down of sheeting to collect the considerable amount of spatter and the fact that the average hand-held hopper gun needs to be refilled every five seconds. so the render still has to be taken up to the top of any scaffolding you're using. Once applied the render still needs levelling off with a feather-edge and floating, so it's just the initial application that seems speedy.
An auto-feed render-gun, with mixer and pumped action would be better. Expensive to hire and difficult to source, though, and possibly overkill for the average house. One of those and a team of three or four, however, could render a large building pretty quickly.
Whatever method you use, you still need at least two coats, with the base coat well-scratched - apply any render too thickly with any technique and it will crack. Where the auto-guns come into their own is when you're rendering with a bulky, light render based on hemp shiv or flax. then they're excellent. it's a pretty large-scale industrial process though, and not recommended if you haven't done it before.

 

[Inspector John]

Thanks for your advice Gervase

Have a good Christmas

 

[bigdoozer]

We use a hand held gun every day (we work) spraying a lime based system that is quite gritty. IF the compressor is big enough (Talking CFM not PSi) we can apply 40-60 mtrs per day without working too hard. Our system is not trowled or flatterned thou'. Biggest house was two coats @20mm, over 600mtrs in 3 weeks using 10 tons of powder. 3 guys. So if you have a large area, still faster I think. Masking with Corex pvc sheet (8x4 about £4 at Selco) doors & windows can be masked in about 1 minute each. (Corex is the stuff they make estate agents signs from). I think the render gun method is great for using on a regular basis (ie as a business) but takes some practise.

 

[Gareth Hughes]

Bigdoozer It's interesting that you have, in your past appearances here, claimed to have no commercial interest in a spray-on render system whose "beneifts" you praised, and yet now you tell us that you work - spraying on render :evil: Please go away before I lose my temper again...