Tobye1
New Member
Does anyone have any experience? I've used the vinyguard silvergrey 88. Then 2 x epoxy HB primer. All good. Until today when I've sanded the primer back a little and theres now soft patches underneath.
Jotun Paints
- Thread starter Tobye1
- Start date
upcountry2
Well-Known Member
Vinylguard 88 is 1 pack primer,
Penguard HB is 2 pack.
Perceived wisdom is that you can overcoat 2 pack with 1 pack, but not the other way round.
The solvents in the 2 pack have reacted with (softened) the 1 pack, sometimes you can get away with it, but it looks unlikely in your case.
Sorry to tell you, you may have to strip it off, easier said than done.
Penguard HB is 2 pack.
Perceived wisdom is that you can overcoat 2 pack with 1 pack, but not the other way round.
The solvents in the 2 pack have reacted with (softened) the 1 pack, sometimes you can get away with it, but it looks unlikely in your case.
Sorry to tell you, you may have to strip it off, easier said than done.
Quandary
Well-Known Member
Strange decision to put the 88 on before the epoxy, it is not what Jotun recommends? I did the reverse without problems, Penguard HB followed by the Vinyguard, because we are in Scotland I used the low temperature additive in the epoxy mix, that was a couple of years ago and I have been impressed with the durability.
sarabande
Well-Known Member
Have a word with SML on 01285 862132. Ask for Eddy.
Even if you didn't buy the VG or Epoxy from them, they will help you. Very good customer service.
Even if you didn't buy the VG or Epoxy from them, they will help you. Very good customer service.
VicS
Well-Known Member
I fear upcountry2 is probably right.
You dont say what you are applying it to but very probably no primer is need before the Penguard HB
Always read the manufacturers product data sheets !
You dont say what you are applying it to but very probably no primer is need before the Penguard HB
Always read the manufacturers product data sheets !
Caer Urfa
Well-Known Member
+1 I have used Jotun paints for many years without problems, upcountry2 is correct you can apply a one pack onto a two pack but you can not put a two pack onto a one pack, normally I use Vinyguard 88 as the primer before applying my antifoul.
Also agree with sarabande give SML a call they are very helpful people but in this case I am afraid it might be too late and you will have to get it all off to prevent further problems.
Tobye1
New Member
Spoken with my supplier this morning. And confirmed that Vinyguard 88 can be applied first. Basically sealing off any unknowns before the Epoxy goes on.
It seems that Vinyguard 88 doesn't harden that same as normal paints. I've basically been too heavy handed with the sander and softened it.
Confirmed by scraping, sanding and general messing about with it on one of my keels to satisfy myself that its not all going to drop off!
It seems that Vinyguard 88 doesn't harden that same as normal paints. I've basically been too heavy handed with the sander and softened it.
Confirmed by scraping, sanding and general messing about with it on one of my keels to satisfy myself that its not all going to drop off!
upcountry2
Well-Known Member
As I said, sometimes you can get away with it, if your supplier is Shepherds I would trust what they say.
Not so sure about the rest.
Fingers crossed...
Plevier
Well-Known Member
I think your supplier is misunderstanding what Jotun say. Is it a non marine supplier?
Jotun say you can apply it OVER epoxy (or over unsound antifouling) as a tie coat for new antifouling and you can overcoat it with alkyd, acrylic or antifouling.
It is not suitable for under epoxy.
Look at https://www.smlmarinepaints.co.uk/files/library/files/DATA_SHEETS/Vinyguard_Silvergrey_88_data.pdf
Penguard HB can be used on gel coat, steel, aluminium, bronze and concrete. See https://www.smlmarinepaints.co.uk/files/library/files/DATA_SHEETS/Penguard_HB_data.pdf
Tobye1
New Member
Well. There's no way I'm starting again a week before launch. I did read somewhere that Vinyguard can be used UNDER epoxy. It took a lot of digging to find that info. And although it had jotun branding on the document thats not to say it was a jotun produced doc. I'll be honest I'm 50/50 on it. I'm aware that epoxy shouldn't go on top of single pack as a rule. However I was informed that Vinyguard was the answer. And in places where I haven't been aiming for perfection with a sander it is still solid. I'm now off to bury my head in the sand and hope for the best :/
VicS
Well-Known Member
Having done a bit of digging around I think you may be Ok.
The Vinyguard is solvent based and dries by solvent evaporation. The solvent mix used in the Penguard epoxy is very similar that in the Vinyguard. Although some softening of the Vinyguard may occur when you first apply the Penguard they should not be totally incompatible in the way that a two pack finish is incompatible with an underlying oil based gloss paint. More like applying new antifouling over old!
Tobye1
New Member
Hopefully ok Vic.
P.s. keep an eye one the SWOA facebook page. Will post an album of my full renovation next week
P.s. keep an eye one the SWOA facebook page. Will post an album of my full renovation next week
nemodreams
Well-Known Member
I used Penguard HB - direct onto gel, wet sanded to 240 grit. Not the easiest stuff to get any surface finish on - been rock solid for ten years - and it was not a silly price !
Its also not that hard - ie it will wet sand smooth if you are fussy. More an epoxy based primer than a true 'epoxy coat'. Good stuff though.
It does have a bit of solvent in it I fancy - ( my gelcoat was red and one could see a bit of colour leech ). So I would trust it to hold onto a single pack coating. Problem is how dry the single pack was before overcoating. It will dry up hard - take a while. I doubt it will off fall off.
Its also not that hard - ie it will wet sand smooth if you are fussy. More an epoxy based primer than a true 'epoxy coat'. Good stuff though.
It does have a bit of solvent in it I fancy - ( my gelcoat was red and one could see a bit of colour leech ). So I would trust it to hold onto a single pack coating. Problem is how dry the single pack was before overcoating. It will dry up hard - take a while. I doubt it will off fall off.
