Epoxy, seam seal and Gravitex

[andeep]

Hi there,

I currently have the underside of my car in bare metal. I want to epoxy prime it with lechler epoxy, seam seal all the seams and then finally undercoat it with Gravitex.

I understand that the epoxy has to be recoated within a certain time period or it will have to be scuffed before coating it. I want to apply the seam sealer and gravitex without having to scuff the epoxy.

Therefore after I spray the epoxy how long should I leave it for before applying the polyurethane seam sealer, then how long do I leave the seam sealer to dry before applying the undercoating?

 

[Flapdisk]

You need to read the data sheet for the epoxy you bought and see what the fully cured, touch dry and overcoat times are, I would guess about an hour before seam sealing, but that's with the one I use.

 

[MG David]

http://www.paints4u.com/pdffiles/29107.pdf

The above link takes you to the data sheet.

 

[andeep]

I have had a look at the datasheet and I can't really understand it. Would someone be able to take a look at it and explain what it means?

DRYING TIME
Air drying at 20 °C
Dust-free: 15-20 min.
Handling: 5 h
Sanding: 18 hours
Through-drying: 48 hours
Low bake:
at 60 °C: 30 min.
at 50 °C: 45 min.

SUGGESTED OVERCOATINGS
Dry-on-dry cycle:


After 8 to 10 hours at 20 °C from the application it can be overcoated with knifing polyester putty.


It can be overcoated by itself if used as a sealer-filler or by other epoxy and polyurethane sealers-
fillers. Generally it is used in Industrial Car Refinish in “two products” cycles, that is overcoated
directly by the enamels of LECHSYS range: ISOLACK – ACRITOP.
Wet-on-wet cycle:
Wait from 1 hour to 24 hours at 20°C and overcoat directly with two-pack polyurethane enamels
(ISOLACK-ACRITOP).

 

[Rocketman]

I'd also be tempted to go over the gravitex with at least some clear coat. Reason being that will give it a nice smooth finish which won't be such a muck magnet and be easier to clean.

 

[JonnyAlpha]

I'd also be tempted to go over the gravitex with at least some clear coat. Reason being that will give it a nice smooth finish which won't be such a muck magnet and be easier to clean.

Agreed - I posted a very similiar question a while ago either here or on the Mini Forums, after a lot of research and advice I will be applying Epoxy Primer, Seam Seal, more Epoxy Primer, Gravitex Stone Chip. I was also then advised to apply a Top Coat (Gloss) to help to wash off road muck otherwise the Stone Chip becomes a Bi** to keep clean.

 

[andeep]

Looking at what the data sheet says can anyone tell me how many hours after spraying I should seam seal? Then how many hours after seam sealing should I apply the Gravitex?

Many Thanks

 

[Flapdisk]

I would say anything between 10 and 18 to seal and 48 to gravitex

 

[Rocketman]

Just be a little bit careful with gravitex over seam sealer, depending how thick some areas are seam sealed may need a bit extra time to fully go off.

 

[andeep]

Can anyone else shed some light on what I need to do, or even decipher lechlers tech sheet?

 

[JonnyAlpha]

Can anyone else shed some light on what I need to do, or even decipher lechlers tech sheet?

I am no expert but looking at the extract of the data sheet you posted it says:

'After 8 to 10 hours at 20 °C from the application it can be overcoated with knifing polyester putty'

So I'd guess if you can apply putty after 8 to 10 hours seam sealer should be OK?

It also says that it can be handled after 5 hours (at 20 Degrees, so if its colder wait longer), so the above assumption fits.

And then 48 hours from painting the primer before you overcoat with Gravitex, not sure how long you should leave the Seam Sealer, so I'd agree with Flapdiscs timings of

I would say anything between 10 and 18 to seal and 48 to gravitex

 

[andeep]

I emailed Lechler about recoating times and they have said 24 hours is the maximum amount of time before recoating:

Good afternoon,


that’s right, if left for over 24 hours sanding is necessary.


Best regards