barrryg 1 Posted September 30, 2014 Hello all , im afraid as a first time model builder ive had a bit of a misshap , im currently building a Mercedes benz actros and I have just sprayed on the primer . I thought id done a good job until on closer inspection I seem to have areas with runs in them , gutted doesn't come close to how I feel right now , so is there a simple solution you guys can give me to fix this problem , many thanks Barry Share this post Link to post Share on other sites
Percymon 2184 Posted September 30, 2014 Give it at least a few days to dry and harden then sand back with wet n dry I'm afraid. If it's run into detail areas like door shut lines etc you may be able to recover these with fine scalpel . Alternatively you could strip the primer off and start again 1 Share this post Link to post Share on other sites
KEV THE REV 2319 Posted September 30, 2014 As Percymon said , cut the primer back after a few days etc . If you are spraying in cold temperatures this can cause runs , and if the paint is not shaken / stirred properly - good luck Share this post Link to post Share on other sites
mr crispy 2293 Posted September 30, 2014 Agree with the above advice. I'd add I f you're using spray cans I find giving them a good shake and then standing them in hot water raises the temperature which increases the pressure, especially good when spraying in cold conditions. It'll give you a much finer spray or help you get to the end of the can without spluttering. Share this post Link to post Share on other sites
alfagta 126 Posted September 30, 2014 yip, block sand it back , a matchbox makes a nice small block and keep it gentle , taking extra care to not sand in ridges (the block helps keep preasure even and well spread) then wet sand with very fine wet or dry , finish with 1200 and 1500 , if you get back to the plastic stop sanding that part , all you want to achieve is to flatten the runs back to the same level as the surrounding paint . for future reference , get a jug with some hot-ish water and stand the paint in it for 5 minutes , shake for 2-3 minutes then back in water for a minute or two then a quick shake of 30 seconds and spray , dont hold the can too close , around 20+cm from surface to be sprayed , allow time for each 'light' coat to dry , around 5 minutes in a warm room , 20 minutes in a cool room , use long sweeping strokes that extend beyond the work , my best tip for painting is tea and cake ! , really ,, get some nice cakes and sit and have a cake and a cuppa between coats . you have to be portly to drive a big rig , right? take your time and you will get sorted 1 Share this post Link to post Share on other sites
KEV THE REV 2319 Posted September 30, 2014 Let us know how you get on with it , and remember the primer coat is just that - a primer , it doesn't have to be very thick , just a key coat - so light coats are all that are needed , same for finish coats , build them up in light coats, in the warm , and a flat down in between coats if needed Share this post Link to post Share on other sites
barrryg 1 Posted September 30, 2014 Thankyou for the advice all , im afraid it looks like was was too eager to get it done without doing the research first , hopfully after a couple of days ill go and look at it properly and pray it isn't too bad , its a pity I don't know anyone who would do the painting for me as I would had never touched it myself , oh well you live and learn as they say. Its a tribute truck to my late father so it has to be right. Barry Share this post Link to post Share on other sites
barrryg 1 Posted October 1, 2014 Just an update for you , I went and looked at my handy work now its dry and to my surprise it all seems to have dried ik , there may be one area on the drivers door that needs sorting , apart from that im very happy and id like to thank you all for your help. 1 Share this post Link to post Share on other sites
KEV THE REV 2319 Posted October 2, 2014 I thought that might happen as primer paint will level out to a certain extent , but still flat it off all over before spraying any other coats - Share this post Link to post Share on other sites
bromvw 744 Posted October 2, 2014 Glad you have managed to save the job Barry . As said always pre warm you spray cans . I have found Halfords hard plastic primer to be excellent on tamiya hard plastics BTW . Share this post Link to post Share on other sites
barrryg 1 Posted October 2, 2014 Thanks for your response bromvw , I used Halfords primer for plastic so it looks like I made a good choice . ive noticed some areas don't quite have complete coverage and you can slightly see some white showing through but I don't think that will be a concern . Now all I have to do is put on the main coat , do you or anyone have any ideas on how I should do this and how many coats etc?many thanks Barry Share this post Link to post Share on other sites
bromvw 744 Posted October 3, 2014 Barry a good quality finish is down to one thing PATIENCE . Very light coats allowing them to dry completely between coats . I would allow at least 1/2 hour in a warm and dry area . Your final coat is best done when the one before is semi dry though . Then give it a few days to fully cure . At this stage you can wet sand any imperfections before giving it a couple of light coats of clear . Just take your time and you will get a good finish Share this post Link to post Share on other sites