Anti-rust primer before fibreglass/filler?

[walty666]

Hiya,
Just been working on removing some rear wheel arch rust (not on the bongo, but my other half's car). Got rid of most and treated with Jenolite but now need to patch up some holes with fibreglass and filler over. I want to treat the area with anti-rust primer. Should I spray the bare metal with a coat or two of anti-rust primer before applying the fibreglass and/or filler or will this affect the bond? Am I better off applying the fibreglass and/or filler directly to the metal?
Cheers
Ross

[haydn callow]

Unfortunatly in my experience.....whatever you do the rust will be back within 9 months.....it shouldn't cost very much to have the rust cut out and new metal welded in......then you tidy it up and paint........much better job and should last a few years......you will need to have it cut out a couple of inckes bigger than you think to get rid of all the rust.....

[mikeonb4c]

Unfortunatly in my experience.....whatever you do the rust will be back within 9 months.....it shouldn't cost very much to have the rust cut out and new metal welded in......then you tidy it up and paint........much better job and should last a few years......you will need to have it cut out a couple of inckes bigger than you think to get rid of all the rust.....

That has been my sad experience. Despite my best efforts and a really good invisible respray, there is a 'sweat line' back already where filler meets metal. Mind you it has stayed at that, and is still a great improvement. Luckily too, the rust on mine is confined to one or two small areas...so far

[helen&tony]

Hi
Depending on how much rust there is, you can get good results with "Lead loading". You can get kits from a classic car restoration supplier
Cheers
Helen

[mikeonb4c]

Hi
Depending on how much rust there is, you can get good results with "Lead loading". You can get kits from a classic car restoration supplier
Cheers
Helen

Is this what I've heard years ago called 'leading'. If so, it has always been on my mind to consider it as it could be an ideal solution for (limited rust on wheel arches). BUT I thought it was a specialist skill, and if you got it wrong you could warp the steel panels. Can you tell us more about it, as it does sound like it could be a good option to try (esp. if it can be done DIY with some molten lead or whatever.

[bigdaddycain]

Seeing as the repair is sat there awaiting some paint, nip to your local paint supplier and treat the uncoated bare metal with "acid etch primer" It's relatively inexpensive, sands nicely, and is compatible with conventional primers. Don't forget to allow a little extra time for the primer to fully dry (in this cold,damp, weather) before you attempt to "flat it off"...