Wooden deck prep

[PhilH]

HI There,
 
I am refurbing a baggy 2 and all the varnish has lifted. I believe that it has been epoxy/2 pack finished. What grade sandpaper should I use to prep her? Can I use an orbital sander on her. (please say yes as I dont want to block her down)? Tips and hints would be welocmed.
I will be also painting the hull which is 2 pack. Any sanding, prep and finishing tips?
 
Cheers,
Phil

[Interested Party]

I would leave the orbital sander in its box.  Much damage has been done with them.  There are sanders that are much better for the job though, I will let someone else pipe up with recommendations. 
Heat and chemical stripper is normal.
Here is a link to some info from the CVRDA - Classic and Vintage Racing Dinghy Association.
If that does not work put this in:
http://www.cvrda.org/wp-cvrda/
Basically, the harder the stuff is that has been put on in the first place, the harder it will be to get it off.
If it has lifted, its coming off.  A patch repair might keep you afloat, but it will look unsightly.
Cheers
Steve H

[Biniou]

For the hull, no polyurethane painting under the water line. (see: http://www.international-marine.com/)

[Tim Gatti]

Phil - removing two-pack or epoxy from a thin ply deck can be a pain. If you are sanding with an aggressive grit (60/80) then you have to be really careful not to go across the grain as this, as I'm sure you know,  will show up when you re-varnish. This can happen even with a random orbital sander. 
It's also very easy to sand through the top veneer and that will not look at all pretty when the deck is re-finished.
Try a hot air gun and a really sharp scraper to see if it will lift off that way.  If not try something like 'Nitromors' - the one in the yellow tin that you neutralise with white spirit.  Again you'll need a very sharp scraper and be prepared for multiple applications, depending on how well the finish has been applied.
As for the hull - are you removing the paint or just prep'ing the surface for a new coat? You don't say what finish you plan to apply. Just remember that you can apply one pot over two pot paint finishes but not the reverse.
Depending on the condition of the old paintwork you generally need to give the whole hull a good sanding to give a key for the new coating (80/120 grit), then fill, sand and prime any surface repairs necessary; then undercoat, nib off and apply top-coat following paint manufacturers instructions.
The entry about polyurethane paints below the waterline really only applies to hulls permanently immersed - one or two-pot polyurethanes are fine for dinghy hulls which tend to spend most of their lives out of the water.
Good luck with the refurb
Tim

[Biniou]

Boero, Nautix, International, all painters say: one or two pot polyurethanes are not made to resist more than 3 or 4 hours in the water...So dont sail all a day!8)

[Tim Gatti]

Hi Biniou - given that the majority of wooden dinghies in the UK probably have hulls finished in one or two pack marine paint or varnish from reputable manufacturers, I really wouldn't be too concerned about their ability to maintain the integrity of the hull - even if sailing all day.
 
If the stuff is so poor at keeping the water out how come the manufacturers are selling it at such exorbitant prices - it's fit for purpose; don't worry about it.
Tim
PS I also know of several well known and successful dinghy sailors who just use ordinary gloss paint from the hardware shop - and their hulls always look immaculate.

[Biniou]

Yes, manufacturers are not clear. Facts are against them.:-/

[Philheath (Guest)]

Has anybody used Jasco paint and epoxy remover. If soI how did you get on with it and where do you get it from?
 
Cheers 
Phil

[Tim Gatti]

Phil - I believe the Jasco product is American and is probably unavailable in the UK as it contains dichloromethane - now a banned product in the EU.
 
The UK equivalent is the one I mentioned in an earlier post - Nitromors Craftsman Paint Stripper (in the yellow tin) which is now only available in the 'new formula' version which uses 1,3 dioxolane and dimethoxymethane instead of dichloromethane - but it's still v nasty stuff as it also contains methanol which can get into bloodstream via skin and inhalation. Not to be recommended!
 
Links to the spec/H&S COSHH data sheets for both products below - you will see that they are pretty similar in composition apart from the dichloromethane substitute.  Be aware of the Health Warnings on the COSHH sheet and follow usage advice - it can make you very ill if used in confined spaces with insufficient ventilation and is caustic, so cover skin, wear rubber/nitrile gloves and goggles.
 
Cover all areas not being stripped with newspaper or polythene - it's surprising how little splashes and flakes of old paint/varnish saturated in the stripper can make a real mess of the bits you didn't want to strip!
 
Finally - I haven't come across anything that strips epoxy in the way that paint peels off, it's generally a case of using at least 5 or 6 applications and shaving off a thin layer each time.  If you find something that does - please let me know.
 
Tim
 
Here are those hyperlinks....
 
Jasco : http://www.wmbarr.com/ProductFiles/Jasco%20Premium%20Paint%20&%20Epoxy%20Remover%20%284015-26E%29%205-17-11.pdf
 
Nitromors Craftsman: http://www.restexpress.co.uk/acatalog/Nitromors_Craftsman_Dichloromethane_Free_COSH.pdf