Monday, August 28, 2006

primer coat peeling a bit...

Now that I have my sailboat hull in a dry garage.  I have noticed that the primer coat I put on last summer is peeling in spots.  Also, the fiberglass strips I placed on a couple of the scarf joints are loosening.
 
What do I do now.  Sand the whole hull down and reprime?  Totally strip all of the priming off and reprime?  I will replace the fiberglass no matter what.  I originally went with the fg strips because I couldn't afford to glass the entire hull...  Now I am thinking about "biting the bullet" and glass the whole hull.  Can I go over the primer coat or should I sand down to bare wood to get the best adhesion of epoxy to wood?
 
Any suggestions are welcome.
 
I am just about done fileting the entire hull interior - thank God!  Then I can prime and paint the interior and get busy on decking, seats, etc.
 
Andy

9 comments:

  1. Andy,   Did you wash the anime blush from the epoxy coat before priming?   -Kruez-

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  2. I was using West Epoxies 105/207 on the scarf strips.  No I didn't see any blush forming on the scarf strips before I primed so I figured I was safe.  As the hull sat out in all weathers and the bilge area where the taping failed was sitting in water several times between bailings I suspect that this is why the fg pulled away from those scarf seams.

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  3. Andy,   It's allways good to wash the epoxy surface down with mild detergent or mild solvant. You can't see the blush. It's just there. Kind of like a wax that forms on the surface of curred epoxy. Pick at it with your finger nail and see if you can easily lift the primer coat around the peeling areas. If you can not than you should be fine; just wipe the small areas with a solvant and touch-up with additional primer. If you can; then the peeling is going to get worse and you'll need to sand scratch the surface and re-apply the primer.   -Kruez-

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  4. Green is correct. Zinser is a good product, and many a work boat has there topsides protected with latex paint products.

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  5. I see at the store that there are two Zinser products, one is latex based and one is shellac based.  From the labels, either will work with marine paints.  Which do you two reccomend?   Andy

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  6. That is a good question Andy.   I suppose it depends upon what you your going to top it with. I you are going to run latex over the primer then use the latex primer. If you are going to run a marine grade enamel then use the shelac based product. Or use the recomended marine grade primer under. It's all about the cost vs. longevity tradeoff.   Also think about this. I beleave it was Greg Rossel that said; "A boat that has both painted and varnished surfaces is much more handsome then one that is all painted or all varnished."   -Kruez-

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  7. Kruez, I think I will go with the shellac based one.  Also, yes I will have both painted and natural brightwork when I am done.  Thanks for all of the help you have given me over the years.   Andy

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  8. Greenmacus:   I am pretty sure the label I saw was for the Bullseye 123.  I will recheck of course before I buy to make sure it is not the Bin product.  Thanks for your help   Andy

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  9.  WOW, what a mess.... I'll try to help you out here.. Please excuse me from being a windbag  for a moment..    First when you apply primer, be sure sand the surface smooth with 80 - 120 grits papers, and wash down the area with denatured alcohol to remove grease and other impurities, remember "SILICONE" is your worst enemy... I had an idoit sprayed silicone spray lube on my primer, and man that stuff is nasty and mean... Needless to say, paint wont even stick to it... But, anyway I use System Three "high build epoxy primer" to coat over epoxy before painting. Just make sure your surface is dry and clean...   As far as your starf joints is loosening... I haven't have any trouble in that department.. Are your wood are dry and clean? did you mixed your epoxy correctly? There are so many factors that can cause your joint to fail..   Are you planning to re-glass the entire hull? Geeeee, that "a big job and it can be expensive" Because you would end up using 200 plus sandpapers to do the job.. Epoxy is tough stuff to sand after it fully cured.. I would just sand down to epoxy coat with 80 grits paper, wash the area with alcohol, and re-apply epoxy and fiberglass in area that troubles you.. No need to sand entire ship..

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