Gesso who?

[Zac]

I've not had any call to use gesso so far in my burgeoning career, but think I might need to for a custom paint job for a client. I'm g(u)ess(o)ing (sorry) that I will only ever rarely need to use it again in the future, so am wondering; what's the consensus on using ready mixed as opposed to making your own? Good enough? Waste of time?

I'm not going to buy a spray gun (as recommended by Vintage Frames in this excellent thread: viewtopic.php?p=157798) just for the occasional job so will be resorting to brushing it on. Am I being naive, should I have some proper training first or am over-thinking this and it's actually very straight forward?

Any advice/tips/tricks/gotchas gratefully received.

[Gesso&Bole]

What sort of finish are you wanting to achieve, and what are you starting with (wood variety/profile)?

Acrylic gesso and RSG gesso are very different, depends what you are trying to do.

Give us a bit more context, and we will give you more opinions

[Justintime]

Proper training is never a bad investment and has often been the boost I've needed to move forward in a new direction.

[vintage frames]

If you're only talking about a paint job, then the ready mixed gesso will do. What you're looking for is something to cover and fill the wood grain which will print through whatever paint you choose to use.

The traditional gesso which you make on site is the most user friendly when it comes to exacting a perfect finish.
It is however a bit of a faff to spread evenly which also means you have to add layer upon layer so as to build up to a sufficient thickness. This allows you to sand it all down to a dead flat and even polish, just like marble.

You can do the same with the ready made gesso but the only problem there is that acrylic gesso is much harder to sand and finish.

If your moulding profile is a simple flat shape then you could just use Fine Surface Polyfilla or Ronseal 2 x part Woodfiller for more instant results.

What ever system you use it is essential to sand with the correct grades of sand paper.
Ebay will get you small quantity sheets of 180 grit and 320 grit paper.

[prospero]

It depends on the type of finish you want. If you are doing water gilding with real gold leaf then the traditional gesso that
you mix yourself is essential. Mixing it is is a craft and there are many vids on YouTube that show you how, but there are
different formulas/methods according to different individuals. You will need an electric hotplate and a double boiler as well
as various tools. Equipment and materials are not very expensive. The hard part is sanding to get an immaculate surface.
Real gold is pricy - imitation not so expensive. Laying the leaf needs practice - don't expect to get it right first time.

If you want a painted finish with powder gilding you need only prepare the wood to a lesser extent. I fill the grain first with
diluted fine surface filler and then apply a couple of coats of thick emulsion. The stuff intended for ceiling and uneven walls
is the best stuff as you can sand it easily for a smooth finish. Forget acrylic gesso as it tends to be hard to sand.

That's the short answer.

[prospero]

This one has no gesso and no leaf gold on it.

It was done as I described. OK, it's totally phoney but all finishes are when you come down to it.
I prefer the term 'faux'.

[prospero]

So is this....

[Zac]

Thanks everybody for the excellent, as usual, advice.

I'm not planning anything fancy like gilding, the client chose an R&H A186 moulding (https://www.roseandhollis.co.uk/products/a186/) which I got in Obeche, and they just want a simple matt finish with a Farrow & Ball eggshell which I was going to either varnish or wax.

I'm now thinking a diluted fine filler, undercoat and top coat with plenty of sanding in between should suffice.

Do I need to go finer than 320 grit?

[vintage frames]

Yes, in that instance, diluted fine filler should do.

You could go with 3 x coats, sanding 180 grit between and then finish with 320 grit.
Wear blue vinyl gloves to save your finger-tips.

That should give you a fairly flawless finish.

[prospero]

Remember when men used shaving soap and a brush? That's exactly the way to apply the filler. Scrub it in with
a wet big brush. Then 'polish' with a jiffy cloth as it dries. I've just done a few......

As for sandpaper grits, I never use anything finer than 120. If you take your time applying the primer coats - brushing over
with an unloaded brush as it dries, the sanding you need to do is minimal. Just basically remove any small nibs and lumps.

** Remember to clear all the dribbles under the rebate.

You can spend a lot of time (and effort) smoothing out but after a certain point you are doing a lot of extra work for less improvement.

[Zac]

"Remember when men used shaving soap and a brush?" Some of us still do!

Great advice, thanks all, much appreciated.