I keep coming across the same problem.

In the final stage of flatting and polishing minute white speckles appear in the epoxy. 

My process, 1 st coat , coating epoxy , 8 > 10 hr cure @ 20*

hand 120 dry sand , brush off dust , vacume.

2nd coat , coating epoxy 8 > 10 hrs cure @ 20*

hand sand wet - 320 > 600 > 1200 > 1500 > 2000

everything looks good at this stage even flat finish no blemishes really, just needs buffing up...

so 

machine polish - ( cheap electric car plisher ) onto wet surface -  farecla standard compound G 3 ( SPECKS APPEAR  > farecla ploshiing compound G10 ( SPECKS REMAIN )

it does not always happen but it doeas happen a lot 

any ideas

Ben

I would say that the compound is filling in minute holes in the surface, that is unless these white spots wipe off with your finger?

I agree it is probably pin holes. What I have heard some do is to wash out the pinholes with alcohol and use air to blast out the compound residue.

Take some black boot polish and put a few coats on and buff. The black will fill the pinholes and the rest will be removed when polishing.

Yes its a crude way to make things look good but it works.

Fred    

Thanks , i think your both right but im not sure that boot polish will help as im not doing it on carbon but multi colored patterned cloth. 

and i dont have air tools.

I have previously posted with this issue and found another fix by washing with wd40 but its not perfect and i would dearly love the problem to not occur or at least know what im supposed to try to do to stop it from occurring..

I have just gone back to the surface starting at 320 wet and it took a lot of sanding to get rid of the speckles. and then i did the same process but did the compound and finsh by hand to keep a close eye on what was going on. 

Its better but its still not perfect.

The picure is a BEFOR shot

Here is a picture of what i was dealing with...

I have had the same problem in the past and this is my cure, rub over the marks with a black white board marker ( non permanent) and then buff with a cloth and spray with a clear coat. Yes I  know it sounds like a bodge but it could salvage the part.

Chris

try to de-gas the epoxy before you apply it. do you have access to any form vacuum equipment?

i dont have access to any vacuum equipment im afraid .. i do stir very slowly and let the resin stand for at least 5 mins before i use it. and i scoop off any collections of bubbles first. also use a heat gun to get rid of bubbles that seems to work very well while im using it  (ie i see tinny bubbles pop) ... Also this is the top coat (brushed on, its synthetic brush and i re-use it , keeping it in acetone between jobs and drying it before use) . its coating resin and im polishing it back to be the top finish. I wonder if what im getting is dust from the surface of the sanded coat below ... i always brush then vacuum ( with a vacuum cleaner) and then brush off with a soft brush, as ive thought it right to steer away from tack cloth of acetone or anything really between coats. Im still a bit miffed ... if anything here sounds or or unnecessary please let me know.

Thanks

do you heat the resin before mixing or after?

I can recall fred advising another forum user of a technique to remove air bubbles which involves  the resin being pored (when mixed) from a height (around 12-18 inches I think) slowly into another container apparently this causes the air bubbles to pop. worth a try cause its free!

other than that build a degas chamber with some Perspex sheet and tube silicone'd together, make a rubber gasket for the top, piece of Perspex with a small hole in it for the lid and vacuum the air out with a small vacuum cleaner. it just may work!

good luck!

hi  neilb

 I like the sound of making a de-gassing chamber but not having seen what one does i cant quite picture what your describing ...

could you expand a little ..

ben