Hi All,
I will bet this has been asked before but here we go. I have just built a Simplicious from the foamies scratchbuilt useing Depon 3mm and I have used clear tape to hold parts together whilst the glue has dryed/set, I have removed the tape ASAP after setting but now I am spraying the foam with water based acrilic where the tape has been it shows very badly. what have I done wrong.
other wise it is a great little plane and cant wait to fly it.

The tape has most likely torn the depron, and made many small "wounds". The paint will only be as good as the surface its applied on.

In order to fix that, you have to smooth out the surface so its smoothness is equal to the areas where you did not tape. One way to do is to use a water based primer. Or, lightly sand it.

Hi latte
Thank you for your quick responce do you think that if I fill with light filler and re spray I could ge a result.
how would you hold together the foam parts for glueing to not get foam damage. I did notice that on the build blog that he used Magic tape is this less sticky that selotape.
regards
biggles8
(Peter)

hi mate when i damage or tear of the deprons smooth surface i use red devil light weight filler its the best. most foamy builders use it when you go to the hardware or shop you know you got the right one as the container will feel empty when you pick it up it sands easy to.Tod.

you may also try "polycrylic" water based spray by minwax, once you give your bird a couple doses of this you can paint it with any thing and it will be smooth . hope this helps

If the glue on the tape I use is too tacky, I simply de-tack it by applying the strip of tape to my clothes. (pants being most efficient :P ) I use that trick a lot when I mask for painting also, and I am afraid the mask will tear the paint off.

I hate to hear that. I struggle with that issue too. It really sucks to pull up your tape and have it take part of the foam with it. I have done a couple of things on Dollar Tree and Cellfoam 88 which I think is simular Depron?

On thing that works for me is to temper the foam a little with a heat gun. That is...heat it just enough where you just starts to melt the outermost layer of foam. (practice with a scrap) This seems to give the foam a very slight hard shell that doesn't usually doesn't pull off with your tape.

I also use light pink/purple tape. (think it might be 3M) It isn't near as strong as the regular stuff and goes easy on the foam. Hope this might help?

Thank you all for your sugestions all.
next time I am in town I will look for sutable products to use.
not sure where to look for acrilic primer though here in the UK

may want to try some low tack masking tape what we call it in uk.

its a very low tack tape used around windows etc etc. its low tack means less residue is left behind after removal. may help with depron better than selotape and other heavy tack tapes.

THanks again to all used low tack (rubbed of the bulk of the tack) now i'm flying.
happy building
biggles
(peter)

Lightweight spackle
an assortment of several grades of sand paper
Minwax Polycrylic and fine wet sanding paper from 600 to 1000 grit is a foam modelers best friend for finish preparation. once you get a slick surface you can brush paint on a paint job with water based latex acrylics and it will look like a million bucks.