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Prep for 2nd coat of 2T Epoxy
9 replies to this topic
Posted 29 March 2007 - 11:55 AM
Wondering if any sanding is required to bond the second coat to the first?
Posted 29 March 2007 - 01:29 PM
If it is totally cured, I would wipe thoroughly with alcohol, scuff the surface (I personally like 800 grit for this), and clean again with an alcohol rag. This helps eliminate amine blush residue problems. You're ready to recoat.
Posted 29 March 2007 - 02:26 PM
I do the same. Light sand, wipe with alcohol and recoat. The next coat will cover any sanding marks.
Posted 29 March 2007 - 06:46 PM
I have done both with and without sanding the base Devcon coat, and have not noticed much difference either way. However, the alcohol wipe definitely will remove dust/oils, etc. from handling. Both Dean and Ranger are right that light sanding will be invisible through the second coat, so I can't argue with sanding. Might help even everything out and surely will not hurt the bond between coats.
Posted 29 March 2007 - 06:59 PM
I also light scuff between coats. I also think this helps the 2 coats bond better.
Posted 29 March 2007 - 08:51 PM
I always rub down with 700 grade 'wet n dry' paper the stuff they use on car paint finishes) this has an alarming effect on the clarity of the finish almost obliterating the paint job underneath but the next coat of epoxy brings the clarity back and you would never know it had been sanded at all, I then clean with alcohol before the second coat. It is however not recommended to coat over a fully cured coat of epoxy because you end up with one coat on top of the other and it is never fully bonded.
Posted 29 March 2007 - 09:24 PM
This question came up a couple of years ago on a rod building site. The answer from a guy who developed finish epoxies for a living was that if you recoat within 24 hrs, the 2 coats become a single mass. Epoxy cures to close to "final hardness" in 24 hrs but may continue curing for as long as a week. That said, I lightly sand the first coat. First, it points up any goofs or high/low points. Second, you can see better where you need to brush if you're coating a matte translucent surface versus a gloss transparent surface.
Posted 01 April 2007 - 11:14 AM
steel wool and 220 for any rough patches if they are present has worked well for myself
Posted 11 July 2007 - 10:57 PM
I also sand between coats only when I have an flaw of some type that I wish to remove by sanding.
I also apply the second and third coats within 24 hours, usually within 8 or 9.