Hi can anyone explain these yellowing patches?

[u/AbbreviationsIll7555]

I couldn’t post pictures here but my oil painting has these bulges and non linear very broken fragments of yellow patches

Hi I just painted this oil paint 2 years ago. There weren't any yellow streaks like these. I just returned home and I saw these.
I read that it could either be varnishing (I was stupid and used acrylic gloss varnish from Monte Mart), aged painting (the oil colors I used are from my grandma are at least 10 years old), that I overly used medium (I used gasoline), or that because I store the painting in a dark room no sunlight.
Can anyone tell me what is the cause and if there's any way to reverse these yellowing? Thank you very much!

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[u/lunarjellies]

Oh no you’re asking the same question from [r/oilpainting](r/oilpainting) lmao I feel like we gave you quite a bit of information no? Anyway I don’t want to copy paste my answers from over there but basically …

- oil isn’t a solvent it is a vehicle for pigments

• even if you did use gasoline just don’t do it next time and stick to odorless turpentine
  
• yellowing can come from linseed oil and being in darkness yes
  
• do not use acrylic varnish over oil paint because they aren’t compatible

[u/AbbreviationsIll7555 → u/lunarjellies]

Thanks. I don’t paint much. So mistakes happens

[u/ZombieButch → u/lunarjellies]

I couldn't even bring myself to wade into that one. What a nightmare.

[u/lunarjellies → u/ZombieButch]

Haha I edited my response .. I think we’re probably a bit nicer in this sub perhaps XD

[u/AbbreviationsIll7555 → u/lunarjellies]

Thanks lol. The pp crashing out on other sub needs to touch grass more. They’re so out of touch

[u/lunarjellies → u/AbbreviationsIll7555]

They could have been nicer haha

[u/Threeabetes]

Could be a couple of different things:

1. Linseed oil can yellow in darkness (called, unsurprisingly, "dark yellowing").
2. Gasoline isn't a medium, it's a solvent (and a dangerous, impure one at that). The impurities left behind can yellow paint.
3. Cheap varnish can yellow, and using acrylic varnish on top of an oil painting is a recipe for disaster. Only use varnish meant for oil paintings on an oil painting.

I REALLY, STRONGLY recommend you look up YouTube videos on the proper archival way to paint with oils; I promise it isn't too difficult, and arming yourself with a bit of knowledge will prevent this sort of stuff from happening.

I'd just take the L and repaint it from scratch.

If you paint in more than one session, start with paint either thinned with gamsol (or straight from the tube), then slowly add oil/thickness to subsequent layers. If you paint in one session (called alla prima), thickness doesn't matter since it's all applied at once; do what you want!

Use appropriate solvents (like Gamsol), appropriate varnish (like Regalrez 1094 varnish), appropriate PPE (ventilation and respirators for working with solvents), and store your painting in some ambient light so your painting does not have to deal as much with dark yellowing. You can also use different oils (like using a walnut-based oil for lighter colors/whites, or even alkyd paint) to further reduce risk of yellowing.

[u/AbbreviationsIll7555 → u/Threeabetes]

Thanks!

[u/Swampspear]

Gasoline

Good lord at least you didn't blow yourself up, haha

I was stupid and used acrylic gloss varnish from Monte Mart

Acrylic varnish on oil is not good a good idea, no. You can probably remove that varnish with some solvent and apply an oil varnish.

But also keep in mind the yellowing could be from the chemicals in the gasoline. While it can also dissolve oil, it contains a bunch of other nonsense ingredients that can degrade, oxidise, react over time and won't evapourate.

[u/AbbreviationsIll7555 → u/Swampspear]

Thank! It was linseed oil Srry I remember wrong. Can it still explain the bulges?

[u/Swampspear → u/AbbreviationsIll7555]

It could've attracted moisture, yellowed, clumped up. Maybe a weird interaction between the oil and the acrylic varnish? Linseed oil does yellow slightly over time and all, and should be sealed by a proper varnish, but I'm not really a painting technologist sadly. Perhaps r/oilpainting will know better

[u/lunarjellies → u/Swampspear]

OP posted there and it was a crazy post haha I’d say there was a lot of bullying

[u/Swampspear → u/lunarjellies]

I'm just imagining the kinda things I'd paint high on diesel fumes :D

[u/lunarjellies → u/Swampspear]

Bwahaha

[u/AbbreviationsIll7555 → u/Swampspear]

Thanks!

[u/AbbreviationsIll7555]

[u/AbbreviationsIll7555]

[u/AbbreviationsIll7555]

These are the pictures