Painting advise needed
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I hope other forum members can help you here. On our own boats boats we used not one of these systems. The in my view money machines for the producers. After the last coat of Epoxy we use DD lack. DD lack is a derivative from Epoxy. Of course sanding of the last layer with grid 80 sandpaper is important as well as cleaning with Acetone. Unter water we use Epoxy/Tar mixture with fused silica. No better protection. Then we where trying diverse underwater paints. All sea animals and plants liked them very much. I had the impression the where like fertilizers for them. In Spain we had friends who worked at the marine. We got uw paint from them and yes, these worked. Other ideas please.? Bernd |
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Esteban,? did you cover the hulls with glass or cloth?? I covered my hull with three layers of epoxy and two of epoxy flowcote which is basically epoxy with aluminium oxide flakes. This was done with a mohair roller. The layers is applied over the first at the tacky stage so that all the layers form one single compound in the end. The result is a bit of a stipple effect which calls for a lot of sanding before painting with two part motor paint. What I have found is that after eight years the difference in expansion co-efficiant between the marine ply and epoxy layer causes a lot of hairline cracks and the boat loses its water impermeability. This was most notable on the sides that saw most sun or UV, the bottom was ok. This necessitated the top surfaces to be covered with glass, sealed and painted. My advice is: -Cover all surfaces with glass or the (polyester)material talked about a month ago usepeelply to give you a good prepped surface. -Use S-Fair 600 epoxy fairing compound to smoothe the surface left by the peelply. -Sand -Paint with two part car paint -For the bottom use antifoul of your choice -Sail a lot Regards Philip Malan On Wednesday, April 6, 2016 1:11 PM, "toma? ho?evar tomazhocevar1@... [k-designs]" wrote: Hi Bernd Now better weather is about to come and it is perfect time to prepare a boat.
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First;
- epoxy 1 coat, virtually as a sanding sealer as per Bernd's reccomendation, sand. - glass cloth applied with straight epoxy, then: - 1 or 2 filler coats with small amount micro balloons or something like West's fairing filler wet tacky on tacky - sand, then 1 coat straight epoxy resin (as per Gourgeon reccomendation) Then your epoxy undercoat or epoxy primer undercoat x2, sand,? then your various topcoat x2 above waterline, ?and antifouling paint of choice below waterline On no account add any filer of any description to the epoxy that you are applying the glass cloth with- it wont wet the glass cloth out If your finish is good enough after the final coat of epoxy, then you could leave out the primer as Bernd says, but for a first time boat painter it's probably good insurance to use it regards Bryan |
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The boat was painted ?from the beginning. Epoxy shrink over time (years). There was no UV on the epoxy before it cracked, Remember to paint the top horizontal surfaces with a very whitish or light colour, just off white otherwise you will not be able to walk on them from the heat. Philip On Wednesday, April 6, 2016 11:43 PM, "wavesailor75@... [k-designs]" wrote: Thanks Philip, These are the layers I think I'm going to use: Plywood Epoxy? Epoxy Fiberglass Cloth Wetted out with 10% Silica Fiberglass Cloth Wetted out with 10% Silica Primer Primer Primer Paint? Paint Bottom Paint? Bottom Paint I think you answered my question in that since the bottom paint is ablative I should paint the entire hull first and then put on the bottom paint. This seems like alot of layers (and expense) but I'm wary of putting in alot of time, money and work into something and then messing it up because I lost focus at the end. I think the primer is important but I don't think the paints are as big deal as long as they can stop UV.? On that, the cured epoxy I've played around with maintains good pliability. I wonder if it was the UV that broke down your epoxy topsides and not CTE mismatch. -Esteban? |
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Hi Philip
Very interesting information. I am a bit surprised reading about your experience. Revering to the cracks in the Epoxy layers. Plywood and Epoxy have almost the same expansion coefficient. The cause is in the Aluminum coefficient 22) which has an extreme expansion coefficient in respect to plywood ((almost nihil (3)). The flowcoat is meant to protect steel! So it was not the UV which was helping to deteriorate the surface but the Al content. Just Aluminum powder product Epoxy against UV. Normal Epoxy must be prodected against UV. ? But the development of Epoxy products is an ongoing story. There exists now poisonless hardeners for Epoxy for example and the are more resistant to UV rais as well. So the can be used as topcoats.??See Duckworks Epoxy products. ? Cheers ?Bernd ? |
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Hi Bernd (or any other member who feels qualified to answer my question?
 ?),I accept your?advice that DD Lack is a good solution for the last paint layers above water.? However, when googling?for it I I found a bewildering variety of brands and manufacturers.? And some of them do look like "money machines for the?producers" to me, for instance Epifanes?sells a 750 cc tin for EUR 53! So, would you have a concrete advice which Brand to use? Then on the epoxy/tar mixture to be used as antifouling. Sounds also like a good idea. But what type of tar should I use (manufacturer, brand..) and where can I get it?? Thanks in advance! Robert |
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Hi Robert
Yes, paint is a pain in... But general any good Polyurethan paint will do. Now do nor go to boat shops to buy the paints. There other shops who sell PU paint. It is also so different from country to country. The last time I was buying PU paint in the Netherlands (last year) it was if I record correct € 42,- per KG. More or less the same paint I was buying in Spain for € 25,-. So it is very difficult to give prices for paint for different countries. It would be good if builders from different countries would share there findings, give hints and addresses.? As tar you need wood tar! if you have found them mixing relation is 50% tar, 50% Epoxy. This will be the base. Hardener as for 100% Epoxy! Fused silica about as much as necessary to get a thick paint like consistence for a smooth surface. Cheers Bernd |
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Hi, I do not know about this tar paint. I have used normal car and truck paint which work a lot better than the PU paint I used on my first boat. I am talking about two part paint used as instructed. Cheers Philip Malan
On Thursday, February 1, 2018, 4:41:02 PM GMT+2, sidziaszczyk@... [k-designs] wrote:
This is good online shop in Poland. A lot of brands, goodbye proces. www.farbyjachtowe.pl Slawek 01.02.2018 1:55 PM "Bernd@... [k-designs]" napisa?(a):
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The tar is no paint but a prodection for the underwatership.. You was asking ,or not?
I am not married to any paint manufacturer or! When you or somebody else has good experience with a given sort of paint, tell us. A friend had to be at the start the next day for his first nonstop around the world attempt. But there was still a spot which needed light blue paint. The only shop which was still open was a sort of "penny" shop. Got the paint for Gulder 3,5 (US $ 1,3). After the world around trip there was some damage, but the paint was still in place ;-)? |
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Thanks Bernd!
After shopping around a bit, I finally bought a tin of??International Primocon primer and a set of?International Perfection top coat blue 216 from?12seemeilen.de. This brand seems to hold the middle ground between top quality / top?price and basic quality / low?price. I need it now already (although I started my project six weeks ago) because I am ready with the rudders and need to paint them. I will report on my experience with these products?later. Cheers Robert ? |
Bernd Kohler
Philip Malan
bryanandmarycox
Robert Twiss