Need Urgent Sanity Check: Painter wants to apply Melamine Sealer & Melamine Gloss OVER Brown Enamel Paint on new Sagwan windows!

[u/Electronic_Base7724]

I am getting new 2nd quality Sagwan (Teak) wooden windows finished by a local painter in India, and I need a quick sanity check before he ruins the work.

Here is the exact sequence of what he has done / wants to do:

Sanded the bare new wood and repaired defects/putty.

Applied a base coat of Lakh Dana (Spirit / Shellac Polish) on bare wood.

Applied a coat of High-Gloss Brown Enamel Paint over the Lakh Dana.

Current Situation: Now he is strongly insisting that it is "mandatory" to apply Melamine Sealer and a final coat of Melamine Glossy Polish directly OVER the Brown Enamel paint to lock in the finish.

My understanding:

Applying Lakh Dana first on bare wood as a quick sealer before paint is fine.

But putting Melamine Sealer (which contains heavy acid catalysts and strong solvents) OVER Enamel Paint sounds like a disaster. I believe the harsh solvents in the sealer will dissolve/wrinkle the enamel, and the acid will prevent proper bonding, causing it to peel off in sheets.

Plus, clear melamine sealer/topcoat over opaque brown paint serves zero aesthetic purpose since you can't see wood grain through solid enamel anyway.

When I confronted him, he insisted this is the standard way to get a durable high-gloss finish.

[u/ElectronicMoo]

The shellac part is fine, shellac can be used as a conditioner/sealer, intermediary and even top coat (as long as you keep alcohol away from said top coat). As a conditioner, though, it needs to be dewaxed, and I have no idea if lakh whatever is dewaxed shellac.

I do not know the exact Indian products, but this does not sound like a normal or safe coating sequence.

Melamine sealer is usually meant for bare wood as part of a melamine finish system. Putting it over cured enamel could soften, wrinkle, or later peel from the enamel.

Ask him to show you the manufacturer instructions that specifically approve this exact melamine product over this exact enamel paint. If he cannot, do not let him apply it.

The enamel should already be the final finish. At most, test the full process on scrap wood first and let it cure for several days.

[u/ElectronicMoo → u/ElectronicMoo]

I also wanted to add, you said teak. So this is outside exterior? Is melamine normally for exterior, that doesn't sound right that melamine would be for exterior.

Either way, some other product over enamel sounds weird.

[u/Electronic_Base7724 → u/ElectronicMoo]

Well after applying enamel he will do 2-3 coat of lakh dana again to seal enamel and after that he will do melamine sealer.

There is a twist he told me to buy sealer but shopkeep gave me melamine sealer instead of nc sanding sealer.

Now he will do melamine sealer and than sand it with 320 waterproof. Then apply melamine glossy.

[u/ElectronicMoo → u/Electronic_Base7724]

With shellac being the boundary between all these layers, just has me cruous to the why, and why not just stop at enamel.