Hull stripping

[sheppard]

First, many thanks for the very useful replies to our question '?New engine'. We took everybody's advice: got a second opinion, now getting a Beta in to replace the dead Bukh.

Now it is on the hard having the new engine installed, I looked at the hull. It has many assorted layers of paint, looking messy and patchy, all of which are on top of an epoxy layer(s) done 10 years ago using International Paint's Gelshield.

We want to strip it back to the epoxy, but all those asked at the yard tell me sanding (by me) will take forever and could damage the Gelshield, and also that sandblasting will also risk the Gelshield. Does anyone know of a paint stripper which (a) works and (b) will not harm the epoxy?

I would be grateful for suggestions for the best way to prepare the hull for a fresh coat of paint.

 

[tyce]

this job is well worth doing but i agree with the yard, i have done a hull myself and it does take forever, and the other methods are sure to damage the epoxy, so it will be interesting to see if a antifoul remover solvent would work

 

[Talbot]

Removall will do it.http://www.paint-stripper.co.uk/removall_paint_stripper_marine.htm give them a ring and get the right one for the task.

Its good I have used it.

 

[Neil_M]

I'm considering stripping mine this winter and applying preventative Gelshield before trying a hard antifouling next year instead of the fertiliser I evidently painted on in the past. Do you have to spray the Removall on or will brush/roller work?

Also, probably a daft question, but how do people manage to strip/epoxy whilst on a cradle? /forums/images/graemlins/confused.gif

 

[Birdseye]

I tried International paint stripper. It worked but I'm not sure its any easier than the traditional scartsen (?) scraper. Scraping the hull is a filthy job but it doesnt take too long and because the epoxy is hard, it doesnt damage it unless you go at it like a maniac.

Personally, laziness has overcome Yorkshire thrift (aka meanness) and I'm going to get the hull treated by the Farrow system this winter.

Incidentally, I wouldnt worry too much about the epoxy. Dont they say that they only work for 5 to 10 years? And so wouldnt it be sensible to add more epoxy coats? Anybody actually know?

 

[Pye_End]

Epoxy - depends on whether the hull is dry underneath. If it is probably worth adding to it if it is not very thick. If the hull is damp then all you will do is trap water in.

 

[Talbot]

Roller will work, but you cant get it on as thick as the spray, so will probably need to do 2 coats.

 

[sheppard]

Many thanks Talbot. I will get a tub of RemovAll and get busy! /forums/images/graemlins/smile.gif

 

[bluedragon]

Do you mean antifoul or paint layers? If AF and it's thick, I'd be really interested to know how this works. I had the same problem last spring and having tried the International Paints stripper being used on an adjacent boat on a patch, I concluded that a) it's VERY messy b) it's designed to work on relatively few coats of AF, not about 18 years worth which is what I have! Scraping seems the best way, but I too was worried about gouging the epoxy.

Birdseye mentioned additional epoxy coats. The epoxy on my hull is 18 years old and is in excellent condition according to a recent survey. I spoke with International about applying extra coats and the opinion was "if it 'aint broke, don't fix it"...ie. don't bother. I've also seen a number of hulls where amateur epoxy coats are coming off because or poor surface prep. and/or incorrect coating technique. I've given up on this idea.

 

[Talbot]

If its really thick A/F, it would be better applied with a sprayer cause you can get more on, so it has a better chance of munching its way through th epaint.

 

[sheppard]

We will hopefully do the deed this weekend and I will certainly feed back on how well it went.

However I don't think that we have too many layers - maybe about 5 and I have no idea what they are. We have only had the boat for about 18 months.

Maybe we don't really need to be doing this but just thought we would as we have the oportunity while she is in a cradle and the hull has dried out nicely in the sun!

 

[Phoenix of Hamble]

Best of luck.... took me 5 solid days of scraping earlier this year......

 

[Talbot]

TCM and I found that the best option was to ladle it on as thick as possible, then leave overnight. We then blasted it off with a high pressure water jet. The water neutralises the removall, and it will dry on the ground as lumps of paint which can be collected and disposed off. We also used a sandvik scraper

to get down to bare grp, but you wont need to be quite so dedicated as you are re-painting. I do recommend a very coarse sandpaper rubdown and a further wash before painting.

 

[sheppard]

We are hugely impressed with the feedback that we have had on the two questions we have posted in the last few weeks.

Just wondering though - why arent you all on your boats enjoying this lovely weather. you can't all have boats stuck waiting for new engines like us!

 

[bluedragon]

Oops...you just found out our little secret...we aren't boat owners at all, just forum geeks! /forums/images/graemlins/smile.gif

 

[PCUK]

Birdseye, I think you are confusing epoxy coatings with coppercoat type antifoulings. Epoxy last forever or at least a lot longer then polyester resin. Owners with boats built using epoxies and paying a premium price would be very upset!!
"Dillunette Gel" is the stuff I use for antifouling stripping. Also eats skin so take care!

 

[paul_williams]

tried these so called strippers a few years ago, can't say I was impressed. try getting hold of a 'limbide' scraper. you get them from decorators merchants. most of us at barrow sailing club are now firm converts. they blade is made of tungsten carbide, so it lasts a long time and makes short work of many layers of antifoul.

 

[roger]

I used a Bosch power scraper wit reasonable success but its a nasty job. I turned blue for a few days (AF colour) I used Tungsten carbide blades (hard metall to Bosch). A refinement is to buy a diamond impregnated shapening plate and sharpen the blade from time to time with it (see Bosch instructions).
Oh yes do grind off the corners of the blade(s) to minimise digging in. You will probable dig into the hull from time to time but a bit more epoxy will cover that. When the boat is scraped, epoxied, tie coated and anti fouled she will look super - none of those raised tablelands of old AF.
You should probably use a mask to avoid Copper inhalation but that makes the job even more unpleasant. Only suggestion I can make is to buy a powered respirator (I think APTC do them for about £150.

 

[Talbot]

The scraper I have recomended with the removall uses a tungsten carbide blade. dont knock removall unless you have tried it, and I have.