Help with curing VHT paint

[SteveD CB500K0]

I've been restoring some of the corroded alloy parts on my Triumph.

I have cleaned and rubbed down the foothangers and sprayed them with Halfords Aluminium Engine Paint which is a very close match to the original. Unfortunately, it cures to a matt finish so I though I'd get some VHT clear laquer, spray with that and cure in the oven.

I let the parts "cure" at room temp for 48 hours after spraying with Hycote 450 Clear and then put in the oven for 30 mins at 100 degrees (C) followed by 60 mins at 200 degrees (C)

They have come out yellow.

What am I doing wrong guys?

[Dave M]

Tht sounds weird Steve.

No idea what's happened but good luck in finding a solution.

[mick]

Hi Steve, i'm not sure if it was Den (Spitfire) who had a similar issue when painting his engine casings ?, i can't remember how he solved it though?, hopefully he might see this thread and enlighten us, cheers Mick.

[SteveD CB500K0]

Well, I took it to my local professional (NWR in Maidenhead). He said that I should not bake it! The yellow finish is because i have "burned" the clear laquer!  He suggested to just respray it and leave it in the airing cupboard for a week. "It'll go just as hard as if it was stoved".

I will report back.

[Bryanj]

Thinking back now Steve if its on any cases that get hot it will yellow anyway, had a customer when i was at Mead and Tomkinson had his cx500 blasted and laquered it and it all went yellow

[SteveD CB500K0]

When I lived in Brighton (1976-80), we used Sperex VHT Clear on our exhausts as the atmosphere in winter was very corrosive. It was always fine.

One of the guys tried the cheaper automotive stuff - it went a lovely bronze colour. Not what he wanted but did attract comment!

That's why I've always used VHT or similar since, even when it's heat resistant properties are not important (like my footpeg hanger).

[Spitfire]

Hi guys, bit late on this one, I used VHT paint on my engine parts, sprayed them, let them dry overnight and then baked them in the oven, however for 40 years I've worked with centrigrade, the instructions were for Farenheit, so the silver turned yellow. Then I just oversprayed them and left them well alone ! They have turned out great, the other parts that I baked for the correct time and temperature came out OK as well.

Cheers

Den