external filler onto aluminium primer

[swishtony]

Stripped old pine windows outside back to bare wood. Wood very knotty and sappy so instead of spot sealing with knotting I have totally primed the frames with Dulux Aluminium Primer (Trade).

I was happily using some of the 2 part Cuprinol filler but some of it slightly lifted and didn't seem to take as well as it should. I phoned their technical support line and was told for sure that the filler would only adhere to bare wood, possibly to a water based primer but definitely not to an oil based primer like I have used.

This got me thinking so I phoned a few companies like Polycell and was told the same thing - NONE of their fillers would take to oil based primers/undercoats - they all told me just bare wood.

How on earth then is anyone supposed to repair windows etc. that have not been stripped back to bare wood? There must be fillers that will take to oil based substrates?

Although 3 technical departments have told me the same story I am just not buying it! I wonder if they are worried with todays litigations etc to say anything other than what they told me?

What's the general consensus here? Many thanks for any opinions!

 

[bikeit]

You could try isopon easy sand filler, i use it all the time for exterior filling dries very quick and rock hard, it is used mostly in the motor trade

 

[opps]

So they suggesting that their epoxy resin fillers only stick to waterbased?

BS!!!

I hope that they have phoned all of the car repair shops to tell them that.

I have experienced the same problem as you in the past and it has always been down to the fact that the surface paint was not sufficiently dry.

I haven't used Ali primer for years and so am not sure how many days you need to leave it for