maandag 9 februari 2009

First coat on hull

Primed hull is sanded wet till grit 400 (except for the bottom: grit 220).
When working with your face so close to the hull you keep on finding small spots & holes after every sanding/cleaning. I found it difficult to stop correcting but in the end decided enough was enough.

Then I put the first layer of paint on. I use 2-pack paint, roll it out and tip off with a brush. Before painting I use a tack-rag to wipe off the last dust and I mopped the floor to keep it a bit damp to trap as much dust as possible.
I used about 850 mg to cover the whole boat, much less than I thought I needed. Had to trow away a lot of mixed paint - downside of the two-pack. It has to stand for at least 30 minutes after mixing, so it's not possible to mix some extra in the middle of the paint job as you have to keep on painting wet in wet, else you''ll see an overlap in the paint job.

On the bottom there are still some sanding marks because I didn't sand it as thoroughly as the sides. The sides are not bad at all for an absolute beginner like me. Had a (very) few runs and a few visible brushing strokes and a few spots that show a very slight orange-peel-effect because I didn't sand down the rolled-on primer far enough.

Below a picture to show the gloss after one coat. By the time I'm writing this the whole hull is dull again, because I decided to wet sand out the last imperfections with grid 400 before putting on the final coat. I didn't have much dust in the paint. When painting the rudder I had more problems with dust and rubbish, but in hindsight that rubbish was probably trapped in the brush I used on that paint job. This time I cleaned the brush just before painting.
I also put the second coat on the rudder after sanding 400 grit. The hull will have the same finish after the second coat.
I was not very happy reading earlier this day a comment on Grant's blog, saying it's important the trailing edge of the rudder is no more than 2 mm thick. If I remember right my rudder's trailing edge is about 3,5 - 4 mm (4 layers C+layer in middle+ not very compact laminate).
If I'm going to try to correct this on my rudder, I'll have to do the paint job all over (+ primer). I'm tempted to leave it for now, and first try the rudder as it is.

3 opmerkingen:

Grant Kinsman zei

Hi Menno,
Just wondering what paint system you are using? Looks good. Do you plan to polish after the final coat? less gloss but smoother?

On Ian's full sized plans he clearly marks a 2mm minimum flat for the rudder. Not a maximum. so...

Menno zei

Hi Grant,

I use 'DD-lak', it's a two part polyurethan coating sold/made by Polyservice, a dutch company. I also used their epoxy, fillers, etc.
I'm not going to polish, just put on some marine wax.

I decided to keep the rudder as it is for now and maybe alter it coming winter, should I have problems with ventilation. Arno Molenaar (F31 thrillseeker) mailed me a nice link about sharpening the trailing edge and told me this has worked well on his boat:


Grant Kinsman zei

Good link Menno, thanks, Ian has some information on ventilation and hum.
Looking forward to seeing your boat out of the shop :)