Feeling apprehensive - body prep!

[richie00boy]

P600 is the coarsest really, will need to move up to P800 for metallic or basecoat.

Too fine and there will not be a good key. Although with 1k products which melt together this isn't so critical.

 

[norsa]

to 800 for COB or 600 DG

 

[marlinspike]

It's patch repairs using a can of ready mixed aerosol (acrylic presumably) paint, so it will 600 grade then. Thanks, guys.

 

[SpitfireIV]

Thanks for the replys and help guys!

I've been doing a lot of body prep over the last number of days; filling, knocking the heavy end off with the DA, guide coat, block and repeat, when happy with the filled areas I've put a skim of stopper over them and another guide coat over them and flattened once more. I've been shaping the filler with 80 grit, smoothing and ghosting the edges out with 120 and also smoothing the stopper with 120.


Now, in the first post I have queried about spraying the body with epoxy primer once I had all the filling done, as mentioned I had the body tub hand brushed/rolled with epoxy but I DA'ed all this off as I didnt want to risk any humps or bumps coming through. So, can I still apply a layer of epoxy over all the filler work before my highbuild? I'm concerned that the metal/filler may need to be adequately keyed to accept the epoxy, should I be going to 180 grit to prep for primer; is this too fine for epoxy?

Or, forget the epoxy and just go with etch?

 

[PSweeney]

I'd just shoot 2 coats of epoxy over 120 to seal it, then key that to 180 for high build, then do your flatting and guide coating up to 600/800 as nessessary

 

[langy]

Thanks for the replys and help guys!

I've been doing a lot of body prep over the last number of days; filling, knocking the heavy end off with the DA, guide coat, block and repeat, when happy with the filled areas I've put a skim of stopper over them and another guide coat over them and flattened once more. I've been shaping the filler with 80 grit, smoothing and ghosting the edges out with 120 and also smoothing the stopper with 120.


Now, in the first post I have queried about spraying the body with epoxy primer once I had all the filling done, as mentioned I had the body tub hand brushed/rolled with epoxy but I DA'ed all this off as I didnt want to risk any humps or bumps coming through. So, can I still apply a layer of epoxy over all the filler work before my highbuild? I'm concerned that the metal/filler may need to be adequately keyed to accept the epoxy, should I be going to 180 grit to prep for primer; is this too fine for epoxy?

Or, forget the epoxy and just go with etch?

I'm really not quite sure where to start as you have gone about this an odd way but now you are there I would block it all out with 180/240 and apply 2 coats of epoxy and then wet on wet with 3 coats of primer, then block out to 800 or 600 depending on whether topcoat is cob or solid colour.
etch primer is very old hat and goes on metal only, epoxy replaced it years ago, you don't put etch over filler ever

 

[SpitfireIV]

Thanks for that! I'll let ye know how I get on

 

[SpitfireIV]

Had a busy weekend! Layed on two coats of epoxy primer with a 1.4 hvlp gun after masking up and wiping down. Finish with pretty good out of the cheapo Lidl gun.

Unfortunately it was getting a bit late in the evening so I didnt want to risk going on with the high build (plus I was pretty knackered!!)

Sunday morning then and I gave it a very quick rub with a grey scotch pad, wet sanded out a few little bits and one little run.....theres always one....right? :P Wiped down, tacked ragged and blew off and it was one with two good coats of celly high build.

After these two coats I thinned down another bit of high build and tinted it with a drop of the top coat and misted this over to act as a guide coat for later in the week....

Very happy with the finish! The high build has a nice finish to it, not much orange peel. I'm thankful too that I spent so much time filling and prepping prior to the priming stage as there is very little work that needs doing apart from a few pin holes in the filler that showed up.

I know its personal preference really, but do I wet or dry sand? If dry, what grade do you recommend I start with and if wet, again, what grade? I reckon 400 and work up to 600? I'll be applying a celly direct gloss top coat.

 

[ajlelectronics]

Dry sand and don't leave it out to absorb moisture before topcoating.

 

[SpitfireIV]

Dry sand and don't leave it out to absorb moisture before topcoating.

Thanks. I'm doing the spraying in a poly tunnel so its nice and warm in there, I brought it out for a look but it lives in that tunnel

 

[SpitfireIV]

Sorry, another quick one...

The primer has highlighted a few little pin holes in some of the filled area's that I had missed. I presume a scrape of stopper over these and a sand will sort them, but do you have to spot prime again over these filled pin holes or can the direct gloss go straight on top? The stopper I'm using is a 2K Upol Topstop.

 

[langy]

Sorry, another quick one...

The primer has highlighted a few little pin holes in some of the filled area's that I had missed. I presume a scrape of stopper over these and a sand will sort them, but do you have to spot prime again over these filled pin holes or can the direct gloss go straight on top? The stopper I'm using is a 2K Upol Topstop.

Topstop gold will sort that, 1.4 is a bit small for epoxy, you would usually use a 1.8

 

[SpitfireIV]

I've since given it a good blocking out with 320, this revealed a number of low spots I had missed and some pin holes in the filler. These have been promptly filled and flattened. It's been reprimed and guide coated and I've begun flatting down this time with 400 and finishing off with 600.

Question: While flatting down I burned through the primer in one small spot on a shut line on the rear wing. Bare metal is visible, this will obviously have to be spot primed again. Do I have to go to the hassle of mixing primer, setting up the gun, cleaning etc just for one spot or would an aerosol primer do a similar job? The primer I'm using is a cellulose based one.

Thanks.

 

[MG David]

I would mix up a few teaspoonfuls of epoxy and use an airbrush if I did not want to go to the trouble of using my smallest gun. You don't want to spoil your hard work by resorting to lower quality primer on bare metal at his stage.

 

[langy]

I would mix up a few teaspoonfuls of epoxy and use an airbrush if I did not want to go to the trouble of using my smallest gun. You don't want to spoil your hard work by resorting to lower quality primer on bare metal at his stage.

I would roller it on in such a small area and flat it out, an airbrush will take ages to build up to a decent thickness

 

[SpitfireIV]

Well, yesterday was a big big day! Been looking forward to it for over two and half years!! I got her sprayed up in a lovely shade of Valencia Blue, cellulose. I applied 5 coats then a final heavily thinned down coat to try smooth things out. I'm happy enough with the finish, although it is a bit too orange peely for my liking, but, I guess this can be cut back and polished up? I'm very happy that I got no runs, sags or any form of reactions, fish eyes, solvent pop etc (those things were my biggest fears about spraying!!).

Pictures....

Outside for a last rub down while the spray booth gets a cleaning.

Poly tunnel cleaned out, sprayed down top to bottom with a hose, swept out several times, dried out and then......cleaned again!

All masked up and ready for the final cleandown.

Panel wipe and blue rags were not spared!

Mixed and loaded! Using a Fast Mover 1.4LVLP gun. My regulator mounted on the base of the handle decided to break (of ALL days!!!) so had to go it alone with the wall mounted reg.

Shiney but orange peely.....

 

[norsa]

I think you could call that a success. Well done. Give it a good time to dry out and yes, you could polish it up.

 

[SpitfireIV]

Brought her out into the sunshine at the weekend, orange peel aside.....I think it looks fantastic!! I found it difficult to get any work done I was stopping so often to admire it and hush off little flies or bugs that dare land on it!!

When it does come time to cut back and polish I'm assuming the steps are:

- hand sand (with a block) 1500
- hand sand 2000
- compound with DA - Farecla G3
- compound with DA - Farecla G10

For the compound stage what heads/mops should I be using in conjuction with the different compounds? I think there are different color heads and different colors signify different densitys?

Thanks.

 

[jordan1]

Brought her out into the sunshine at the weekend, orange peel aside.....I think it looks fantastic!! I found it difficult to get any work done I was stopping so often to admire it and hush off little flies or bugs that dare land on it!!

When it does come time to cut back and polish I'm assuming the steps are:

- hand sand (with a block) 1500
- hand sand 2000
- compound with DA - Farecla G3
- compound with DA - Farecla G10

For the compound stage what heads/mops should I be using in conjuction with the different compounds? I think there are different color heads and different colors signify different densitys?

Thanks.

If there is bad orange peel I would start with a courser grade than 1500 then work out to the compounds.

 

[norsa]

Be very careful if its your first time colour sanding, especially in the sharp areas (swage lines arches returns etc) you can go through a hard edge so easily. My advice would be to mask off those hard lines before you start. The flat panels, I would go with a flexi block rather than a hard block as it follows the contours better. Then do your hard lines carefully IF NEEDED by hand. You could go as hard as 800 but just to take the tops off then go through the grades. Celly is much softer than 2k so you may get away with 1500 pre compound. DONT USE A DA. You need a proper concentric action mopping machine really with a compound head, normally white hard foam and maybe a black waffle head for G10 and polish.
Nick
Just my MO. others will have their own way and to be fair, though the principle is the same, ive not sprayed celly in about 20 years.