primer help

[nordvindcrew]

This probably has been covered before, but I could use some concise suggestions. I have a 20' fiberglass rowing double that was laid up as seperate pieces in a mold and then asembled. There is no gel coat. As we used the boat, it became evident that changes in the bottom were necessary. I'm now in the process of laminating new panels for the bottom. They will be put together in tack and tape fashion, so there will be a lot of fairing to do. Specifically, I want a durable low tech primer to protect the hull and get it ready to be faired then painted. Faring material will probably be bondo because the cost is low and the boat is only in the water for an hour or so. Any thoights would be appreciated. Thanks

[gonzo]

Go to any automotive paint store and get sanding primer

[G.G.]

Duratech makes a high build primer and has been around for years and is good for above and below the waterline .Almost every boat co that i have ever worked for has used this product ( primer ) and it comes in white or grey.

[Eagle Boats]

G.G., I believe Gonzo is just as American as you and I. In addition, I have read many of his posts, and he very knowldedgeable.

[keith66]

I think the question of marine or automotive products is a subject for itself!
The Two Gigs i built a few years ago were cut & extended from far older boats, they were built very much on the cheap & were faired with P 38 (Bondo, Car Pud) They live out of the water on trolleys & get used regularly by people who despite our best efforts are not always as careful as they should be!. If they had been faired with expensive epoxy & two pack paint i would cry every time one of them bumps a jetty & gets scratched on the beach or slipway. They are patched up twice a year & are painted with oil based house paint.
On a boat that was built like yours i would initially apply a few coats of Durabuild as its easy to fair & get a good finish.
Lets face it a rowboat will often spend much of its life out of the water so whether or not the filler is waterproof is up to the owner & the boats intended use. If the boat is an expensive work of art by all means use the best materials!

[sabahcat]

I have used this with great results and its the right money

Amercoat CC24 Multi-purpose High Build Sandable Epoxy

http://www.ppgpmc.com.au/default.asp?id=170

http://pacificsouthwest.net/amercoat.htm

[apex1]

in the U S A we buy materials that are made for marine type of applacations .......... Automotive .....WOW . I have to say that it is good to know what type of materials you guys use over there , because in the U S A it would be non acceptable at least in my shop !!!!!!!

You probably would´nt build one single boat if you would have the obligation to build to European standards! That much on that issue.:(
And whats wrong with the auto primer? Do you keep your car in the bedroom all year round?:?:

[sabahcat]

And whats wrong with the auto primer? Do you keep your car in the bedroom all year round?:?:

No, but I keep my boat in the water all year round.

The overall cost of the primer and topcoat is a very small price compared to the endless hours of prep prior to application, I would hate to have to sand failed crap off and do it again for the sake of saving an initial couple of hundred dollars.

Using polyurethanes and epoxy primers primarily aimed at mining equipment, Aircraft and commercial shipping is far far more affordable than the same or similar product being aimed at the pleasure boat market, and the end result speaks for itself.

http://www.cruisersforum.com/attachments/gallery/3/1/1/9/031_31.JPG

[nordvindcrew]

Just to give a little more information about how this boat get used: Trailered to the racesite, usually gets dragged about on the beach which often is nothing but rock. Landings are always to the beach, again usually rocky. Not uncommon to slide right over a submerged rock. In short the boat takes a beating. All I'm looking for is a primer that won't peel off and is a good base for the fairing and top coat, both of which will be low cost, low tech and will need to be re-done often.

[apex1]

Just to give a little more information about how this boat get used: Trailered to the racesite, usually gets dragged about on the beach which often is nothing but rock. Landings are always to the beach, again usually rocky. Not uncommon to slide right over a submerged rock. In short the boat takes a beating. All I'm looking for is a primer that won't peel off and is a good base for the fairing and top coat, both of which will be low cost, low tech and will need to be re-done often.


So, then:
Go to any automotive paint store and get sanding primer
:D

[nordvindcrew]

It sounds like automotive sanding primer is the way for me to go. ..thanks for the opinions and ideas

[Herman]

One of my boats ended up in acrylic car paint instead of marine pu paint, and it was much more durable and scratch resistant...

never submerged for long periods, however. My boats were trailer queens...

[apex1]

What I say..............
`cos that was the original statement: >>>and the boat is only in the water for an hour or so.<<<

[Herman]

I had a terrible fight with the guys from Akzo that supplied the paint. They would not allow me to put it on a boat. Even after explaining that the boat would only be in the water for a couple of hours.

How many hours does your car spend in the rain?

[apex1]

How many years do our cars spend in salt spray? We both live close enough to the sea that we have salty air at least during half of the year. Does that harm our cars paint?
Of course Akzo Nobel likes to sell the marine stuff (at twice the cost).

[Herman]

The front of our offices is so close to the sea, that with high winds, the building is covered in salt. Still everything looks relatively OK (building is from 1991). Only the lights at the entrance did not survive...

Still, using PU (or acrylic, for that matter) in continuous submerged applications is a bad idea. I have seen one of my colleagues go bankrupt on it.

[apex1]

Well, we did not recommend it for a submarine or passagemaker right? But I can see no reason (obviously Gonzo and you too), to go for anything more costly than the automotive stuff.