Do you sand between gesso layers or after gessoing is done?

[JackPaulssen]

Hello there,

I'm still very new to framing. Right now the only way I really know how to finish a frame is by sizing, gessoing, bole, and then gold leaf.

But I've encountered a problem - the gesso seems to me quite thick (1:1.2 RSG to Gesso by weight) such that after 5-7 layers the detailing of the moulding dulls and corners become rounded, etc.

I've read contrasting instructions about whether to sand between layers of gesso, or whether to apply the layers back-to-back and sand at the end (I've been doing the latter).

I figured if I can sand between layers, I might be able to keep the detailing in better shape.

Also, as a near total beginner, I'd really welcome any resources to learn new finishing techniques. Right now everything I know is basically from this one youtube video (

[JFeig]

Thick or thin, gesso, traditional or acrylic, will reduce the detail of any design or detail when applied.

I am having a problem with your formula for traditional gesso in that there is no additional water being added. The formula that I have used for over 35 years has been 2 parts water, 4 parts calcium carbonate(whiting), and 2 parts stock RSG. These are by volume measurements. I do change this basic ratio based on weather conditions. The key ratio for strength is the whiting to glue ratio. Adding additional water will not change this ratio as it will evaporate as it dries. This is the same concept as with any paints solids vs solvent. For a softer gesso use less glue.

[vintage frames]

I've watched a lot of that video and it really does give you a good start to the process of gilding.
Every gilder will have their own methods and formulas but they all converge on the basic mechanism of getting gold leaf to stick to a frame.

I find it very useful to examine the more scientific reasons why certain materials are selected and how they are used. So the methods I'm going to suggest might contradict what you have already been shown.
So buckle up and here we go.

Gesso is used primarily to fill the wood grain, provide a flat even surface on which to lay the gold and to be hydroscopic, ie, eager to absorb water, as this is essential to the water-gilding mechanism.
For all this you only actually need 0.5mm of gesso on the wood.
As long as you've covered the timber, any extra gesso is of no benefit to the gild.

Layering on gesso with a brush is simple and basic, yes, but for zealots only.
Get a small compressor and a cheapish spray-gun - much more civilised.

For reliable gesso, use only good quality RSG. I use Manetti brand.
Mix 400grm RSG to 680ml water.
When melted, make gesso on a 1:1 ratio with whiting, ie 400ml RSG : 400grm whiting.
Stir for at least a minute and then - leave it overnight. This causes nearly all of the dry whiting to combine properly with the RSG.

The next day, when you melt it up, the gesso will be quite smooth and runny. This is good.
I also add a teaspoon of brandy, why? because it helps breakdown the surface tension of the gesso and it smells nice.

To size the frame, paint on two coats of the gesso. No need to be precious about it, as long as the gesso gets into all the nooks and crannies.
Now run the gesso through a fine sieve into the spray-gun.
Spray on the gesso, wait a minute and then spray on a second coat.
And now you're done.
All that blobbiness will shrink down to a fine even coat on drying.

Use 180grit paper followed by 320grit paper to sand the gesso. And a good idea is to use vinyl gloves to protect your fingers.
You don't need to water-polish gesso, just brush it clean and paint on the bole.

For a mirror finish on bole, I sand lightly with 600grit, move on to 1000grit, polish with 0000 wire wool and then high shine with water and a cotton pad.

I hope this helps with your original question. Please come back if you need further and I see you're only down the road a bit, from me here in New Quay.

[JFeig]

I my memory was incorrect regarding my formula as I have not made gesso in several years.

I should have written:
2 parts water, 8 parts calcium carbonate(whiting), and 4 parts stock RSG(16gm per 8 oz. - 235ml)

I also add 15 ml of linseed oil to add a little flexibility to the mixture.

[JackPaulssen]

@JFeig thakns for your input. It's very possible the level of detail loss is totally normal. It's hard to say when you're giving this a go on your own from videos. I've contemplated buying a few nice frames to serve as "models" to copy, as my only real exposure to frames is in museums or private galleries.

My gesso formula is actually taken from Ruth Tappin's youtube channel (link -> https://www.youtube.com/watch?v=yS8gd2jy9gU).

In it she suggests a ratio of 1 part RSG to 1.2 part whiting by weight. The RSG was a 1:10 mixture by volume. So a bit confusing. It's very possible I've misunderstood something along the way and have a slightly thicker mixture than intended - or it could be totally normal.

[JackPaulssen]

@Not your average framer

I've got my gesso on a hotplate with a thermometer in it, I keep it fairly stable around 55 degrees. So I think this is about right?

Where I gesso is essentially a shed, so perhaps the layers are cooling fairly rapidly.

[JackPaulssen]

@vintage frames

Diolch for your lengthy and detailed reply. Yeah, you're not far at all. I see your website has some great content too, I'll check it out. And your IG is full of frames I'd love to emulate one day, very inspirational. That burr elm veneered frame is beautiful. I'll reach out on IG to see if you do any workshops.

In the meantime I'll definitely check out a compressor and spray gun, along with your gesso recipe. I'm using Handover for my RSG - no idea if this is up to scratch, it's just what Jacksons sells. I'll see about trying Manetti. I've also been wondering how to get clean lines when gilding the inner edge of the frame, but it looks like from your website you use kleanedge masking tape - I feel like a bit of an idiot for not thinking of this before.

You mentioned sizing the frame using the gesso. So no pure RSG for sizing? Essentially you're doing 2 coats of gesso with the brush, then another 2 with the spray? Sounds quicker than the 2 coats of RSG and 5-7 coats by brush that I'm currently doing

[vintage frames]

Thanks for your kind compliments.
Do feel free to carry on.

As I said earlier, every gilder will have their own habits and methods but I don't see the need to spend the extra time sizing the frame with RSG.
All you want is to wet the wood with something sticky and gesso itself fulfils that purpose. It also provides an initial barrier on to the timber surface, so preventing the wood from sucking in water from the gesso in an uneven fashion.
This is what causes pin-holes and other defects.

And as I also said, happiness is a compressor and spray-gun.
Squirt boiling water through it to clean it after use.

[JFeig]

To bring back the sharp corners and other detail there are special tools that are used to "re-carve" the fine details. I learned it as the French term "repose" (sp) with a long "A" sound at the end.

https://shop.stuartstevenson.co.uk/prod ... ting-tools
https://seppleaf.com/products/supplies/ ... ving_tools

This is accomplished by rewetting dried traditional gesso and scraping away the excess as with a chisel and wood. After the detail is returned it can be sanded as well when it has dried.

[JackPaulssen]

Hey Dermot, sorry for being a bit dense - but the gesso recipe you suggested:

> Mix 400grm RSG to 680ml water.
When melted, make gesso on a 1:1 ratio with whiting, ie 400ml RSG : 400grm whiting.

Are you saying 400 grams of RSG (10:1 ratio, water to granules). Then add 680ml more water.

Then using this mixture in a 1:1 ratio with whiting?

[vintage frames]

I personally never liked the vague mixing terms such as 1 part of one thing mixed with 10 parts of another thing, especially when they are two different material phases, solids mixed with liquids.

As I said, weigh out 40grm of dry RSG and soak it in 680ml of water.
When melted then measure out 400ml of warm RSG and dump in 400grm of whiting.
Stir for a minute.
If you now leave the gesso overnight, it will be at its best the next day.

In fact, I'm now glad you asked, as I've just read back what I had written in my original post.
Sorry..
40 grm of RSG, NOT 400 grm!

[JackPaulssen]

Ah, great. 40g. That makes sense... 400g left me scratching my head how this combination worked. That's some strong glue

Thanks again!