This is the guide i used when doing my fullface:
Sandpaper: 320grit, 400grit, 800grit wet and dry, 1500grit wet and dry and 2000grit wet and dry.
Scotchbrite: Both red and grey.
Masking tape: Both 1” and 2” wide are handy 3m id the best brand; also you will need any fine line tape etc to create your design.
Primer: Plastic primer, one 350-400ml can should do.
Paint: in this case red, black and grey, I use specialist paint you can mask over very quickly, you must use patience with normal rattle-can paint or it will come off. Of course if you have an airbrush, this is the way ahead, but we’ll assume it’s out of a can.
Lacquer: about 3-4 350-400ml cans, this is generally piss thin so but this from your local body-shop supplier, you’ll get better results and you’ll need less of it, I recommend when you’ve painted your lid, I’d just get a sprayer to paint it, as its very bad for you, so wear a buff or a dust mask at least.
You’ll also need a scalpel and some spare blades, latex gloves. And very importantly some panel wipe (degreaser)
Finally, clean your hands, any grease, oil, or sh1ttyness in general can make paint react at any time and ruin your day big time.
1 Clean your helmet of anything that will come off, get rid of, padding, peaks, bolts etc, stick them by and forget about them.
2 Very important, check the rivets that hold the straps in do not turn, imagine painting and then lacquering out your lid, only for these rivets to spin, which would rip and crack your finish, Sheesh! If I get them and they do, I take them out and replace them with tight ones, but pressing them with a wee g-clamp, just nips them in, be careful though, not too tight!!
3 Now we have a shell with only the straps and polystyrene inside, start from the inside top, (where your bald patch would sit in the helmet) and mask out, you will end up with a kind of Japanese rising sun pattern of masking tape inside, with the overlap pattern, best to use 2” tape for this, its quicker.
4 the rubber bit you chin sits on at the front of the mouthpiece is fragile, if you put tape ion it, it will damage it as you pull it off, so de-tack the tape on this bit by simply sticking it to your jeans and pulling it off a couple of times, if you coax it out and use a scalpel behind it to cut the glue, you can always take it out and glue it back in later, but I’d just mask it.
4 dampen a cloth with some degreaser and wipe it round the base trim (rubber trim on the bottom) this wipes any crap away and will help your masking tape stick, do the same on the face aperture trim, this will stop your rubbers getting tarnished or scratched while you sand the helmet flat.
5 carefully mask off the rubbers with 1” masking tape, the more accurate the better of course, this can make the difference between a good and a bad job, make sure you get the inside covered as well so no over-spray reaches it, as it will be a pain to clean and tarnish your trim, especially if it white. Now do the same with the face aperture trim, taking in the wee windshield at the front of the chin guard, remember to mask off the inside, now check the inside is totally masked off, and you’re ready to get dirty.
6 if you don’t sand your lid flat, you’re gonna see all those tld original designs and pinstripes as bumps under your new design, and it will feel awful when you rub your hand over it, so take your 320 grit and get rubbing making sure you get all the nooks and crannies!
Be careful not to rub too hard, when you see yellow patches appear, lay off that bit as you are through the original design and this is the gel coat of the polycarbonate construction of the helmet, when you’re satisfied its free of the stock design, you have to start prepping for paint.
7 What you need is the smoothest surface you can, whilst maintaining a certain roughness, this is called a key, which are microscopic scratches that the paint can grip on to so it will adhere to the surface of your helmet. This is a fine line: too smooth and no key, hence the paint won’t adhere, too rough and the scratches will show through the basecoat (first paint coat) which obviously won’t do.
8 once you are finished with the 320 grit paper, go to the 400 and do the same again, making the surface smoother still, not rubbing quite as hard, after this, use the 800grit paper, soak it in some water so its not so aggressive and sand the helmet down to a nice smooth consistent finish, the idea of this, is you follow rougher paper with slightly smoother, to remove scratches in steps.
9 once you are happy, dry your lid off, clean the dust away and give it a vigorous rub with red scotchbrite (harsh plastic scouring pad type thing) and then some grey scotchbrite (smoother plastic scouring pad thingy) now you are ready to apply your colour. If your surface is smooth and free of scratches, you shouldn’t need any primer, if you think you do, use a couple of light coats of high-build primer, this will fill any small scratches. Once this is dry, sand flat with 400 then 800, red then grey scotchbrite and you’re there.
10 remove the masking on the rubber trims, and clean with de-greaser again, if you can, give the helmet a blow out to get rid of sanding dust, if not just clean thoroughly, re-apply masking with nice new clean tape (more accurate the better again) cut some small bits up with your scalpel and mask off all of the ventilation vents, be as accurate as you can, the job will look better in the end, you now have a smooth surface and all your bits masked off, wipe the whole thing with de-greaser to avoid contamination and you’re ready to go.
11 when applying paint put on in very light coats, if its too heavy it will nip up and react if there is a hint of contamination, keep going until you have full coverage, cant stress enough, Light Coats! Apply side to side left to right to left fashion, at least a foot away from the surface, here’s where physics come in: the paint we use can be masked on straight away, this wont be the case here, best thing to do is lacquer over the base coat so its safe, leave over night and do stage two the next day.
12 important multi coat information: paint needs a “key” a mechanical grip as pointed out before, when you lacquer your base coat, you must do it within half an hour of finishing it, the reason for this is, while the base coat it still technically wet, putting the lacquer on now will cause a chemical reaction, bonding the paint and the lacquer together. If you leave it longer it will dry, you will then have to veeeeeery lightly rub your basecoat with grey scotchbrite, to make a “key” so your lacquer will stick, so think ahead here!!
13 Once lacquered, leave over night and it should be dry, when it’s dry, you can start the next bit.
14 ok, its dry, scuff the whole thing off with grey scotchbrite to make a key for the next stage, change the masking again for fresh stuff, and de-grease.
15 applying graphic varies, I’ sure masking a design and making your own graphics isn’t really rocket science to most of us, just take your time and use light coats of paint to aid adhesion and drying times, you can cut your own text or get some vinyl graphics made up for pennies, and use them as positive and negative masks for a really sharp look for the descent-world logo we’ll go with vinyl, which should come with application tape to aid accuracy when you apply it, I’ll try and explain as well as possible.
16 Take your vinyl graphic; we have three pieces, the black text (piece 1) the grey outline (piece 2) and the rest of it (piece3)
Carefully take out pieces 1 and 2, this leaves piece 3, the outline of the graphic. De-tack this on your jeans or something, we don’t want it too sticky, as it may not come of or leave gum on the helmet. Line piece 3 up, where you want it on the helmet, mask around it so you don’t get paint overspray everywhere, and paint the area black, let this dry, leaving everything in place, de-tack and insert piece 1 (text) into place where it would sit according to design in the black area you just painted, with this in place paint the whole thing grey, let it dry.
When you pull the text off, it will be black underneath, nice and crisp like, and then pull off the outer (piece 3) which leaves the grey outer edge, and there it is.
17 Final clear coat: having keyed the whole thing after the first coat of lacquer, you are ready to go again, just de-grease and grab your lacquer, before you spray the whole thing, give the descent-world design a few coats of its own, 3 or 4 even, just to cover it well, then lacquer the whole lid, 3 coats and leave overnight.
18 when it’s dry, we go to finish and polish, this is where most fail! Get some 1500grit wet, and start flatting down the lacquer so it’s smooth, when it is, hit it with 2000 grit wet to get the scratches down now go to 2000 then maybe 3000 wet to really clean it up, the reason we gave the logo more coats is so that you can flat the edges away, its flat to the touch, for a bit off class, if your happy that its flat, then start polishing with the automotive polish of your choice, start with abrasive polish like t-cut and work smoother, this is hard work but results can be amazing.
A tip for cool finishing is (before polishing) to flat it down, grey scotchbrite it and lacquer it again, this gives a better final finish and improves longevity of the shine etc.
Leave it to harden for a few days and build it back up, 1x classy spray job!