Penguard HB

oldbilbo

oldbilbo

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This is my first experience of Jotun's Penguard HB....


IMG_3433.jpg



"You never get a second chance to make a first impression"
 
I don't know about Penguard, but I've seen Jotamastic look like that when someone tried to keep painting it on even though it was setting in the bucket. Once it starts to go off you have to stop, and mix a smaller batch the next time.

Pete
 
I have just done two patch coats with Penguard HB onto a completely bare hull with no problem. I suspect that you either have a reaction with what was already on the hull or as others have suggested that it was going off as you were applying. Were you brushing or rolling?
Morgan
 
morgandlm said:
I suspect that you either have a reaction with what was already on the hull or as others have suggested that it was going off as you were applying. Were you brushing or rolling?
Click to expand...

That stretch was bare GRP/gelcoat - where the bootstripe had been and which came off readily. The area below - the main part of the hull underbody - had been sealed a long time ago with VC Tar and layers of antifoul paint. The whole hull had been cleaned by 'soda blasting', gentle sanding for 'key' using a soft rotary scouring pad, and copious washdowns. There were no 'rough patches' where the Penguard HB had been applied lower down and over the black VC Tar..... the coating applied over the bare gelcoat 'stripe' was like the 'backside of the moon' right around, fron tot back.

The ambient temperature was 13°C, had been for some hours, and Relative Humidity around 68% - well within datasheet parameters. I used a lambswool roller on both the upper and the lower areas. The mixing of the 4:1 two-part paint was meticulous, as per the datasheet, and applied immediately. The problem occurred at the start and throughout the job. There has been the suggestion that the hull was colder than ambient, but the one side ( photographed ) had been in full sun for some hours.

I'm stumped..... but I'm spending a precious Sunday morning sanding back. I won't be putting any more on.
 
I stripped my hull and coated it with Penguard HB outdoors back in March, the temp. was below 10C with a strong chilly E wind. I used the Penguard Low temp.additive but at half the recommended concentration. We applied it with a fine roller intending to tip it off with a foam brush but gave up on this because it was going tacky too quickly with the difficult conditions. The finish was still good with just a fine roller texture. To eliminate this we applied a coat of Vinyguard 88, rolling it on horizontally and tipping it off vertically to with a foam brush to give a smooth but not glossy finish ready for antifouling. A high quality 3-4" conventional brush is even better for tipping off but if you have someone with a light touch to do it the foam brushes are cheap enough to throw away as soon as they get tacky.
I think the OP should send a pic. of the mess he has managed to create to SML (Shepherd Marine) the UK leisure market distributors for Jotun, (tel.01285 861590, or at info@smlpaints and coatings.co.uk) they are both a knowledgeable and helpful crowd who I am sure will be able to explain where he has gone wrong and advise how best to sort it out. They can also supply the correct solvent resistant rollers for the application. It must have taken some effort to make such a mess. I looks like it had gone off before application but the pot life is long, something like 8 hours after an induction time of 30 mins.
 
Quandary said:
I think the OP should send a pic. of the mess he has managed to create to SML (Shepherd Marine) the UK leisure market distributors for Jotun, (tel.01285 861590, or at info@smlpaints and coatings.co.uk) they are both a knowledgeable and helpful crowd who I am sure will be able to explain where he has gone wrong and advise how best to sort it out. They can also supply the correct solvent resistant rollers for the application. It must have taken some effort to make such a mess. I looks like it had gone off before application but the pot life is long, something like 8 hours after an induction time of 30 mins.
Click to expand...

I've done that, thanks, and SML could offer no explanation - other than that maybe the hull surface was cold. I doubt that, as the problem occurred ONLY where applied over bare GRP/gelcoat. The hull right adjacent/below which had old, well-attached but abraded VC Tar didn't have such problems, as can be seen.

Yes, it does LOOK as though it has gone off early, but the stuff was applied within an hour of starting to mix - and that took 15 minutes or more. I faffed around making some tea, changing my gloves, finding goggles, etc. but the same problem occurred on the area at the start of application as in the middle and at the end.

They, and I, remain stumped. They're good guys at SML/Cirencester, and sent me some more..... :rolleyes:
 
oldbilbo said:
That stretch was bare GRP/gelcoat I used a lambswool roller on both the upper and the lower areas. The mixing of the 4:1 two-part paint was meticulous, as per the datasheet, and applied immediately. The problem occurred at the start and throughout the job. There has been the suggestion that the hull was colder than ambient, but the one side ( photographed ) had been in full sun for some hours.

I'm stumped..... but I'm spending a precious Sunday morning sanding back. I won't be putting any more on.
Click to expand...

You are using the wrong roller! you should be using the 'foam gloss type', lambswool is for emulsion!! AND did you give the epoxy a good stir before use, biggest mistake by most to give poor results if not stired enough!

Also did you clean the hull with thinners before you applied coating, I assume this is original gel coat as always remember you can apply a one pack onto a two pack coat BUT you should not apply a two pack epoxy onto a one pack.

Good luck, did the same job on saturday for a friend and looks fine.

Mike

 
Last edited:
Hi there,

The temperature of the surface you are painting is as important if not more so than the air temperature; that will be the cause of most of your problems (looking at the above picture) as well as humidity levels, the only way you'll get a decent finish outside is tenting your boat unless its scorching. When i primed my Centaur a few weeks back using the same product i was still very careful about picking which day based on ambient temps and humidity levels and my boats inside a shed.

As mentioned previously a low temp additive is available for penguard HB, i'd use it if painting outdoors and mix in very small batches (around 200 - 300mls) if you've got graduated mixing cups this is easy as the 4:1 mix ratio is marked at four different intervals from around 100mls upto 500ml.

I sprayed the hull of my Centaur using conventional spray thinning the primer around 10% and have also had excellent results rolling this product using foam rollers, these are available from Malcolm at SML.

https://plus.google.com/photos/110182886418433827802/albums/5863649153446631873

cheers roger

www.agentlemansyacht.com
 
I've used HB twice with good results, once very cold with the low temp additive and once quite warm.
I find a very short pile (mohair type) roller best, foam second best.
Lambswool as for emulsion would be disastrous I think, maybe you mean like mohair though?
 
Thanks, 'rogerball0' and 'Troubadour'. I wish I'd had your input before I started. I had only what SML and Jotun's datasheets offered - i.e. not very much and which was IMHO inadequate. I'm very glad I'm not paying someone else for that debacle. I've moved on, sanded down the surface of the Penguard HB to something near flat, and today painted on Vinyguard 88.

I'm rather more pleased with that....


IMG_3443.jpg



and


IMG_3445.jpg
 
I've just had a peek at YOUR hull-pics, 'rogerball', and that's what I call looking great. Inspirational! You must be hugely satisfied with the result of all your work - and rightly so. I'd be most interested in seeing what next you do to your reincarnated Centaur....
 
when applying Pentgard HB it has an induction time of 30 min to allow the chemicals to react once mixed from what I understand from a yard that uses it a lot it should not be applied before the 30min is up
perhaps this was the problem?
 
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