Jotun Penguard HB and Hardtop HB advice, please

[BrianP]

I can also confirm Michael that the method works. A friend painted his small yacht with two pack and it looked awful when he finished. As it goes off it slumps on the vertical surfaces. He was heart broken.
However his brother used to work in car spraying, so they set to with wet and dry and polisher and when finished it looked like a pro paint spray.

I found Perfection very hard work, so I reckon all the two packs are possibly similar. I did find two pack Epifanes varnish no trouble at all, so perhaps their paint is better to use, but it is also very expensive.

Brian

[Paul H (admin)]

Painting is a no-no. Jotun only recommend spraying but rollering is ok because of the thin even coating.

I'm not trying to show off but my Dad was a very good painter who taught me a lot - I can just about get a good result painting Jotun but one bad stroke can wreck the coat.

Stick to rollering a thin, even coat and build up several coats, maybe 3 to 5.

Paul

Sent from my HTC

[Jeremy]

Well, the primer (Penguard HB) went on OK, but was hard work, as it's pretty thick.  Only bad points were that it seems to eat foam rollers faster than I think that Perfection did, and being a bit thick it doesn't fill pinholes in filler (of which, it has to be said, there are a lot on the DP - being a cheapskate and short of time I didn't use a coat of UV Smooth Prime first........).

So far the finish is more warship than show boat, but at least it's not bloody pink any more!

Brian, I found applying Perfection pretty easy, but I was working inside in cool weather.  The secret was to apply a light roller coat and NOT even attempt to go back over it.  As it cured it sort of magically pulled a smooth and very shiny surface, from what had looked to be a bit rough at first.

Having gone through four Screwfix foam rollers this morning I'm going to order some of the solvent resistant ones that SML sell, in the hope that I'll get a better finish with those.

[BrianP]

Thank's Jeremy for the link to the other supplier. How does one choose which 2 pack is best? The Flexi one sounds good for centreboards.

http://www.smlmarinepaints.co.uk/topcoats/two-pack

The XP mentions easily applied by brush and roller!

Brian

[Jeremy]

I'm never sure how to choose, to be honest.  The first two pack I used was Perfection, more than 20 years ago now, as it was then the only one sitting on the chandlers shelves, I think.  Since then I've used a fair bit of automotive two pack, but always sprayed, and on aircraft, rather than boats.  

I only chose the Hardtop HB because it's a satin, rather than gloss finish, which I thought would both better suit the nature of the DP and also be forgiving when it came to a less-than-perfect surface.  It was also cheap!

The XP might well be worth trying, maybe get a small can and see how it goes on before buying enough for the whole boat.  If it does brush and roller well then it may well be ideal.

[Timmo]

Only problem is that rolling on lapstrake doesn't work. Still have to brush to fill the angles!

I do have spray gear, but they only recommend an airless sprayer, and I don't have one of them!

Still, thanks to George and Brian for the 'sand it down' advice. It has cut back well, though it does need another coat now. Hopefully not the disaster I feared, though the finish will still reflect my ineptness.

Tim.

On 30 May 2012, at 12:19, adminHBBR [via UK HBBR Forum] wrote:

> Painting is a no-no. Jotun only recommend spraying but rollering is ok because of the thin even coating.
>

[Jeremy]

I've rubbed the Penguard HB primer down now and have to say it's really pretty good stuff.  The high build allows for a fair bit of surface blemish covering, and it goes hard enough in 24 hours to dry sand without clogging the paper.  I found that the best results were from wet sanding, though, and managed to get a tolerably good surface after an hour or so's work.

I washed the hull down, let it dry thoroughly and have just spent a happy hour or so filling all the thousands of pinholes and bits of glass cloth weave print through with epoxy/Microlight 410 mix.  This seems to have worked better than I expected, as I was able to squeegee the fairly sloppy filler mix hard into the tiny imperfections.

Tomorrow, weather permitting, I'll wet sand it again, then put on a final coat of Penguard, maybe thinned down slightly so that I can get a more even coat.  I now have some of the solvent resistant rollers from SML, so will give one of those a try and report back.

[BrianP]

Just had a chat with technical guy at SML about which Jotun two pack to choose.

For clear coat just one choice the AS clearcoat, but use the high quality thinner H2 to give more time with a wet edge and help bubble release. Some of the spray guys go up to 40% thinners, so no problem going to 20% and doing more coats to achieve a good finish.

For the white hull coat he agreed XP is formulated to be better for brushing and rollering, but it does that by using less catalist, so never goes quite as hard and cannot be burnished like AS. After talking it over he advised using AS with H2 thinner and going for more thin coats which can finally be burnished.

Advised roller and light tip as people have said on the forum.

So looks like we will go ahead with SML and AS Clearcoat on the inside of the Snipefish and white AS on the outside of the hull.

Brian

[Michael Rogers]

I would appreciate advice and collective wisdom, please, about my two-pot painting experience. I'll try to be brief.

Using Jotun Hardtop AS (describes itself as high gloss) over Penguard primer (sanded smooth, obviously). With a view to cutting back with wet-and-dry and then T-Cut to finish off (see earlier in this thread), I rolled on 5 coats, using 10% of the recommended thinners and no attempt to 'tip'. HD foam rollers. It went on well. Final effect looks quite good, semi-gloss with a nice 'glow' to the colour (medium green), feels fairly smooth. Very close inspection reveals a finely textured surface. It's had about a week to cure, so is pretty hard.

I experimented with a small area on the bottom, to see how to get a final finish. I found that with 1500 grade w-a-d it would take forever to remove the 'texturing', so started with RB406 J-Flex 600 grade (which can be used wet), then 1500 w-a-d (wet), finally T-Cut. The result - a glassy smooth surface, but with a slight milky bloom on it (frankly, like the rather tired finish on older cars which I understood T-Cut was designed to remove, not put there!), spoiling the glow of the colour. On a bigger area I think it would look smeary. I haven't gone through the paint, there's plenty of thickness there.

Am I doing something glaringly obviously wrong? If so, please put me straight.

Otherwise, options seem to be -

     - leave well alone, with a less than glassy surface finish. I can live with the increased drag coefficient etc.

     - modify my cutting back technique - ??

     - I've got enough paint left for one more coat. I could put this on with no thinners/same amount/more, and have a go at 'tipping'. Worth a try? Could make things worse.

Contributions gratefully received!

Michael

[Paul H (admin)]

Leave it alone - polishing is a complete waste of time, unless you are entering a competition.

After sailing a few months she will be scratched, bumped and worn by sand and gravel.

Paul

Sent from my HTC phone

[Jeremy]

I've found that T cut can leave a slightly milky looking finish on some paint finishes.  Before abandoning the idea, though, how about trying some polish on the area that you've already treated?  Something like one of the clear glaze type car polishes would probably remove the slightly milky look that T cut can leave.  T cut doesn't contain any polish, as such, it's just a very mild abrasive, with some alkaline detergents help to scour the debris away, I believe.

Overall I tend to agree with Paul, though, it'll pretty soon gain a collection of dings and scratches!

[BrianP]

Sounds to me like things have gone very well and would be best left alone and enjoyed. My friend who rescued his dreadful two pack finish used a professional polisher and cutting compound. I think it's best to be relieved it went so well and save the remaining paint for any touch ups in the future.

I have just had my first trials with Jotun Hardtop AS two pack and cannot believe how well it went after the problems I have had in the past. I used about 15% thinners. It was only on a small area, the top, bottom and damaged area where the gaff sits on a mast I was refurbishing. No slumping, no bubbles in the surface, just a shiny hard finish. I actually used half a foam roller without the rolling. Just as a foam brush.

I have also bought some Hardtop AS Clear. The idea is that rather than 3 coats of expensive epoxy and three coats of very expensive two pack varnish, such as Epifanes, I would just apply 3 coats of two pack Jotun and save a fortune in costs. And get a hard-wearing finish. The supplier confirmed he was happy for me to apply the Clear straight onto the bare plywood.  

Brian

[Michael Rogers]

Thanks, everyone! I had spent the morning coming to the same conclusion.

I remember with my first build (8 years ago) enjoying least this final phase, partly because I set myself impossibly high standards of finishing off. And of course a boat gets used, scuffed etc. It's the showroom mentality, which doesn't have anything to do with what's-that-nice-word-meaning-sailing-in-and-out-of-inlets (from the US East coast I believe). At least this time round this boat (Swallowboats Trouper 12) will have good tough coats of two-pack on, which will be relatively ding-resistant. And it is looking quite nice, though I says so myself.

Your collective sense of proportion much needed and much appreciated. I'm glad your project has gone well too, Brian.

Michael

[eric17]

Hi Michael,
I would like to know how the forefoot of the Trouper 12 is made. This has much to do with Chris Waite's "Premise / Polly Wee" , since the same principle of plywood bending is applied to both hulls. Do you have any pictures ?
Regards
Eric (from France)

[Chris Waite]

Hallo Michael

Did I miss something, or is 'Gunkholing' what you are looking for?

Chris

[Michael Rogers]

Hi Eric

I'm sorry, I don't have any pics of the build - meant to, but never got round to it. I'm not sure if a photo of the current state - painting in the last stages - would help. If you think it might, let me know. My problem is not with a camera - I used to be fairly proficient in the good old roll film days. It's all this digital stuff, and the interface with my computer (with which I have a love-hate, mostly the latter, relationship). However, as I said , let me know. There are some pics of the build process of the prototype Trouper on the Swallowboats website which might help.

I don't know if a description will help. The Trouper has a flat bottom section (9 mm), which is about 2 ft wide at its widest amidships and tapers to a point at both ends. The after end is just at the lowest point of the transom. At the forward end, it comes to a point just short of the forefoot. The lowest strake on either side is 6 mm, stitched/taped to the edges of the flat floor piece except for about a foot at the bow where the two sides are pulled and stitched/taped together forward of the flat floor: this process curls the bottom strakes upwards at this point and forms the beginning of the forefoot. The remaining 3 strakes either side are 4 mm, and their front edges are pulled together to form the bow. The lowest 4 mm strake (the second strake up, counting the lowest 6 mm one) is stitched/taped to the outer edge of the lowest strake along its lower/inner edge, but its upper edge lapstrakes with the lower edge of the next strake up, and the remaining joins up to the sheer strake are lapstrake. The stempost is faux in that it is epoxied onto the curve of the bow, and fared in: around the forefoot it tapers away to the flat bottom.

Clear as mud? Hope it helps. Try the website pics as well. I really will try to post a picture of the finished boat at least. Flat bottom notwithstanding, she is very pretty, and I hope will be fairly stable as well (must be an improvement in this respect on my present boat, which is very tender - also very pretty!).

Cheers           Michael

[Michael Rogers]

Thanks, Chris.

Gunkholing is indeed It (senior moments come thick and fast these days, and merge together into senior episodes: the next stage thereafter doesn't bear thinking about). Am I right about its Eastern US inshore provenance? If not, do you where does it come from originally?

Michael

[eric17]

Oh yes Michael, pics of the (nearly) finished boat also interest me !
I searched all possible photos, on the Swallowboats site or forum, but I have not found any one showing the bow, especially the forefoot and the lower strakes. I would especially like to see how the bottom panels are formed, and if possible a bulkhead at this location, if there is one…

you will find my ideas on one of my pages of our community website http://www.nauticaltrek.com/12723 (all in French allas, or with a butchered translation)

So I will allow you to progress in the control of the #$&%@* machine! I'm not exactly a geek myself, but I go ahead, mistake after mistake: the next stage will be to learn how to use these magical drawing programs...

Cheers
Eric

[BrianP]

Build pictures of the first Trouper are here

http://www.swallowboats.co.uk/content/view/124/



Brian

[eric17]

could you please turn the boat upside down ?
Eric