UK-Cherub Forum

Cherub Chat => Tech Chat => Topic started by: Ed on October 27, 2014, 01:33:43 PM

Title: Paint stripping acrylic paint on epoxy carbon
Post by: Ed on October 27, 2014, 01:33:43 PM
Hello all,

I want to repaint my boat. currently below the waterline she is just expoxy primer so that is done, but the topsides and cockpit were painted with an acrylic, car like paint.

The paint is fairly soft, and it will come up with a scraper (poor bond to the cf) but there is a risk of going through the skin.

Any thoughts on soda blasting.

Apparently it wont go through gelcoat (which i dont have, but i guess 8 year old epoxy primer is very hard) so will it strip the car style paint and leave the carbon untouched.

Title: Re: Paint stripping acrylic paint on epoxy carbon
Post by: roland_trim on October 27, 2014, 01:37:24 PM
Personally am a big fan of 40 grit sandpaper.

Croote converted me to long strips of paper glued to 4x2 planks (or similar) for the underside, but I'm still addicted to the random orbital/40 disks/attached to hoover combination.
Title: Re: Paint stripping acrylic paint on epoxy carbon
Post by: Ed on October 27, 2014, 01:42:30 PM
thanks for the response.

THe issue i have is that it is falling off rather than being sanded off.

the tops sides should be easy, but the interior will take a massive amount of sanding and carefully when it does come of in chips. but not easily enough to ensure no damage to the 200g skin
Title: Re: Paint stripping acrylic paint on epoxy carbon
Post by: JP233 on October 27, 2014, 01:47:06 PM
Keep sailing till it all falls off?
Title: Re: Paint stripping acrylic paint on epoxy carbon
Post by: roland_trim on October 27, 2014, 01:49:07 PM
As a rule, if not stuck down flakes break/vanish under a random orbital. 

Keep changing disks. Find a car spray supplier or similar and get a box of disks (for the same price as a selection pack from B&Q you'll get 100!).

What's the boat? (note we will not mind if not a cherub)
Title: Re: Paint stripping acrylic paint on epoxy carbon
Post by: Ed on October 27, 2014, 02:04:08 PM
Yes sorry it is an I14 Bieker 5 build at the Beer Boatyard

I like to work on it myself and this forum is great for learning and getting help.
Not many UK 14 share what they are doing online.

I guess i am a tart and i want her to look good.


There is a list of fairly major structural modification (weight loss and structural improvements) which i want to hide away as well at the patchwork quilt of repairs that are already there.
I might bounce some of them off you at somepoint if that is ok. ( chain plates currently 1kg in stainless, so laminating a carbon rod into the gunwhales and lashing the shrouds on)
Title: Re: Paint stripping acrylic paint on epoxy carbon
Post by: Phil Alderson on October 27, 2014, 07:42:51 PM
I have not done this on a boat, but having removed some paint from the car with a jet wash at the weekend you could try that on some of the flakey bits.
Title: Re: Paint stripping acrylic paint on epoxy carbon
Post by: Ed on October 27, 2014, 07:53:45 PM
Thanks for the idea Phil, there are some areas i think the skin is compromised so i dont want to soak the nomex, but maybe on other areas.

anyone think soda blasting is a terrible idea in principle for the inside atleast.
Title: Re: Paint stripping acrylic paint on epoxy carbon
Post by: JimC on October 30, 2014, 02:08:31 PM
Soda blasting is quite high risk IMHO. I totally f****d a wooden boat with it. You need to be sure of a big differential between the resistance of the coating and of the substrate, otherwise....
Title: Re: Paint stripping acrylic paint on epoxy carbon
Post by: Ed on October 30, 2014, 07:21:36 PM
Thanks for the input JimC. the acrylic paint is softer than the substrate, but i will take it into consideration.

Going to speak to a company and discuss if i can trial it on a section of hull or foil which i could then repair easily