Spraying nightmare
Posted: Sat Sep 14, 2013 7:08 pm
I'm trying to spray the tops of my wings and the front on my MGB. I'm using cellulose, and I am working outside which is not ideal, but I have nowhere else. I haven't covered it over between coats because I thought a bit of rainwater on it was preferable to a dirty great tarpaulin over it.
I squirted the etch primer on the bare metal and fibreglass wings, then built up with yellow primer putty and sanded back until I was happy with it, then sprayed on the grey primer. For the most part it's gone on ok and looks good, but at the front, a few hours after I had sprayed it, huge cracks appeared in the grey primer. I sanded them back and resprayed, but more cracks kept appearing in different places: still only at the front. So I have set to sanding the whole lot off on the front to have another go, weather permitting.
There's only two reasons I can think why this has happened. Firstly, where I have chased the water out from any crevices with the airline, there may have been muck and grease in it, although I have tried my utmost to work as meticulously clean as possible. Or secondly, where I have sprayed the more complicated shapes around the front, too much paint has built up and cracked as it cured. I think my paint and thinners are ok, because on the wings it is absolutely fine.
Does anyone have any suggestions about what may be causing my problem, or what I can do to stop it happening. I really need to get it done before the weather gets so bad to make it absolutely impossible and before it damages the rest of it.
I squirted the etch primer on the bare metal and fibreglass wings, then built up with yellow primer putty and sanded back until I was happy with it, then sprayed on the grey primer. For the most part it's gone on ok and looks good, but at the front, a few hours after I had sprayed it, huge cracks appeared in the grey primer. I sanded them back and resprayed, but more cracks kept appearing in different places: still only at the front. So I have set to sanding the whole lot off on the front to have another go, weather permitting.
There's only two reasons I can think why this has happened. Firstly, where I have chased the water out from any crevices with the airline, there may have been muck and grease in it, although I have tried my utmost to work as meticulously clean as possible. Or secondly, where I have sprayed the more complicated shapes around the front, too much paint has built up and cracked as it cured. I think my paint and thinners are ok, because on the wings it is absolutely fine.
Does anyone have any suggestions about what may be causing my problem, or what I can do to stop it happening. I really need to get it done before the weather gets so bad to make it absolutely impossible and before it damages the rest of it.