GRP hull issues

[Andy dot]

Hi,

I am looking for my first boat and have an option to buy a cheap 2500£ Dufour Arpege 30 but it has some issues with the hull thai I sm mostly concerned about.

The engine is a yanmar 27 installed in 2020. The cabin lookas okay, the mast seems solid.

Can you please help me decide wether it is worth working on it or walk away ?

Thanks,
Andy

[Orion Jim]

Originally Posted by Andy dot

Hi,

I am looking for my first boat and have an option to buy a cheap 2500£ Dufour Arpege 30 but it has some issues with the hull thai I sm mostly concerned about.

The engine is a yanmar 27 installed in 2020. The cabin lookas okay, the mast seems solid.

Can you please help me decide wether it is worth working on it or walk away ?

Thanks,
Andy

I see decades of old bottom paint which have finally decided to spontaneously remove themselves since no one was nice enough to strip it off through sanding or sand blasting. At some point all bottom paint will do this. It is nothing to worry about. Remedial action is advised or it will continue to deteriorate at its own pace. It’s really best to remove it, barrier coat the hull, and cover with a fresh coat of antifouling paint.

[JPA Cate]

In looking at the pic where the chip is largest, it looks like someone painted over slime there. Bottom paint does not adhere long term to slime.

As Orion Jim said, it looks like bottom paint buildup, and it is long past time to remove it and start over. When you get down to the gelcoat, you'll see if there are any blisters. Soda blasting over sand blasting is easier on the gelcoat, and you don't want that removed. If there are no blisters, you can elect to just prime and paint, without the barrier coat first. The barrier coat is an investment in the future, and you need to get the thickness right. (Talk to the manufacturer.)

The hull looks OK to me, but I'm an amateur.

Ann

[barnakiel]

I see mostly paint damage there not grp damage.


Except that one image with something peeling off in a larger swath. What is it - below the peel - is this bare laminate ?


Maybe it was hard knock when lifting.


If this is bare laminate there, you want to clean the larger area off and then paint over with some layers of epoxy. Normally 4 layers are fine on a boat that sails only in the season. More coats if she permanently sits in the water.


b.

[Andy dot]

Hi everyone,

Thank you for your replies.
The hu itself doesn't look like h ing any bulges that will indicate on blisters.
It worries more on the tiny multiple spots. Is it gelcoat black underneath the red paint ?

b,
Yes, it is laminate there.

[marcjsmith]

Andy, my 35 year old hull had large swaths of peeling paint that looks like yours.

it took some soda blasting to get it back to reliably accepting paint again. with a bolt on iron keel you may be seeing some pitting as well.

its quite possible the entire hull is black gelcoat, and for the below the waterline you'd likley have a primer coat, and many many layers of antifoul paint. the latest being red with a layer or two of green, darker red and cream.

time to sand to down and start over...

[admiral 31]

I should not worry to much, as it all looks like old antifouling

[rhubstuff]

It looks like the waterline of the boat has been moved up a couple of inches, because there is now bottom paint over what was previously a boot stripe. I would investigate why it is so much heavier than the designed weight.

[Franziska]

Originally Posted by rhubstuff

It looks like the waterline of the boat has been moved up a couple of inches, because there is now bottom paint over what was previously a boot stripe. I would investigate why it is so much heavier than the designed weight.

Totally normal for boats on an extended cruise. Most people I know move the underwater paint up, soo that it extends well over the waterline, stops the need to scrape and clean the boot top all the time.



Boats in cruising trim usually are way more heavy then when coming out of the factory.

[rslifkin]

Originally Posted by Franziska

Totally normal for boats on an extended cruise. Most people I know move the underwater paint up, soo that it extends well over the waterline, stops the need to scrape and clean the boot top all the time.



Boats in cruising trim usually are way more heavy then when coming out of the factory.

Agreed. Sometimes the original bottom paint line was put very close to the expected waterline, leading to staining issues, etc. above it. Personally I prefer to have a couple inches of paint showing above the loaded waterline (and then the boot stripe above that if there is one). It looks more correct to me and keeps things cleaner.

[pcmm]

As others have said, what you are looking at is bottom paint adhesion failures. Happens when there are too many old layers of bottom paint. Just needs to be stripped back to the barrier coat and repainted. Typical on older hulls. People ten to put off a full bottom job as long as possible because of expense and effort.