Ok one more stupid question' date=' the ones I have built in the past was cars and I didnt have to use putty to much. But there is alot more on this plane the whole fuselage etc... What is the best why to sand it down I tried a couple of times but still see the seam whats the secret I used 320 then 400 grit and it felt smooth but when I primered it I still see the thing and advise.[/quote']***Filling & sanding come hand in hand,try this method,firstly apply enough filler to actually stand proud of the offending joint,I am not sure which filler you use but they do vary a lot from one type to another,my personal favourite is Squadron,they do two types one is fine green and the other quicker drying but coarser in white.Once the filler has dried and this is best left for 24 hours at least,then you can start sanding,use plenty of water with your wet & dry paper,use coarse to get rid of most of the filler,then gradually getting finer as it starts to touch the models surface,once everything is smooth to the feel you are ready for the primer.After leaving this to dry have a close look at where you have filled,if there are still blemishes then simply knife in a bit more of the filler,repeat the sanding ans add a bit of primer again.The job is tedious but will pay dividends when completed,as you quite correctly say many aircraft kits have poor wing to fuselage joins or seams,the only solution is to file up the mating surfaces and go through the filling process,it takes practise but once mastered like everything else in life becomes easier as you build more models.
