Testing "Hull Strip" - antifoul stripping system

[Larks]

For anyone interested in peel away type paint stripping specifically for antifoul, I've tried some test patches on my H28 on both antifoul and some other hull paint areas.

The product is called "Hull Strip antifouling remover" from Scomar Distributors.

Application is pretty simple, lay it on with a trowel a couple of mm thick, cover it with the provided paper, tape the edges and leave for about 24 hours.

I tried a couple of areas, though first on a strip of exposed resorcinol glue on a deck beam to see if it would have any deleterious effect on my glued strip plank hull:

http://i260.photobucket.com/albums/ii11/Larks_01/P5030023.jpg

lay on the goop

http://i260.photobucket.com/albums/ii11/Larks_01/P5030025.jpg

cover with the supplied paper and tape down the edges

http://i260.photobucket.com/albums/ii11/Larks_01/P5030026.jpg


28 hours later, no discernable effect on the resorcinol

http://i260.photobucket.com/albums/ii11/Larks_01/P5030026a.jpg

[Larks]

The antifouling test, this was at the same time as the resorcinol test so the patch I chose here was over an area of known fibreglass so that I wouldn't damage the glued seams if it turned out the paint stripper was no good for the resorcinol:

http://i260.photobucket.com/albums/ii11/Larks_01/P5030016.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P5030017.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P5030018.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P5030019.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P5030019a.jpg

[Larks]

I tried a bit using just normal kitchen paper - it seemed to work just as well as the special supplied paper:

http://i260.photobucket.com/albums/ii11/Larks_01/P5030029.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P5030030.jpg


http://i260.photobucket.com/albums/ii11/Larks_01/P5030030a.jpg

[Larks]

The supplier advised that it wouldn't work as well on two pack paints, so I gather some of my hull paint is two pack as one patch of above water line paint wasn't affected as much. I chose this area because it is going to need some repair anyway:

http://i260.photobucket.com/albums/ii11/Larks_01/P5030015.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P5040034.jpg

However, inside was a little better, here over a frame with a SS chain plate and some hull area:

http://i260.photobucket.com/albums/ii11/Larks_01/P5030027.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P5030028.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P5030028a.jpg

http://i260.photobucket.com/albums/ii11/Larks_01/P5030028b.jpg





The Verdict? It is expensive (about $180.00 for 20 kg - to cover @ 15 square metres) , it does work - to some extent, it is easier on my wrists than heat stripping (my wrists ache like blazes after a few hours of heating and scraping) and it is safe to use on my resorcinol glued strip planked hull.

Will I use it? At the moment - (on my current budget), the cost doesn't quite equal the benefit, ie it just doesn't work well enough for me to really justify spending the money.

So back to the heat gun and scraper for now - slow and steady, at least while I'm stripping the interior anyway, maybe when I get back outside onto the antifoul I'll be able to afford a tub.

[PeterSibley]

So it just comes off with a bit of a pull ? Any down side ? Is it expensive ? It will certainly make keeping the slip clean and dust free a lot easier .


Thanks for the demo !

[PeterSibley]

Cross post Greg ...I'll read what you've typed first !

[Larks]

So it just comes off with a bit of a pull ? Any down side ? Is it expensive ? It will certainly make keeping the slip clean and dust free a lot easier .


Thanks for the demo !

A very small amount stayed on the paper as I pulled it off, most had to be scraped off just like a normal paint stripper. I gather the paper is really only there to keep the goop from drying out while it works on the paint over 24 hours or so.

[PeterSibley]

So basically , just very good paint stripper ?

Do you ever use a sander? I've got reasonably good at using my 7" Makita with a soft pad from AutoOne and velcro discs .Lots of dust but I use an Airhat too .

[wizbang 13]

I'd shovel the paint off that boat in half a day with the right sander. Fair too.

[Bob Adams]

I suspect if you took regular paint stripper and covered it to keep it wet, results might be similar.

[Larks]

I'd shovel the paint off that boat in half a day with the right sander. Fair too.

Come right over wizz, I'll spot you a carton for it. What is the right sander? I do use a random orbital sander - Makita, after scraping - I can't afford a Festool.

[Larks]

I suspect if you took regular paint stripper and covered it to keep it wet, results might be similar.

I suspect that you are right Bob. Maybe another test this weekend.

[wizbang 13]

For nasty old anti fouling, 5000 rpm with a 7" "spiral cool" backer with 16 grit greenback. As you do topsides, 8" softpad 1000 to 2500 rpm with 36-60 grit stick on discs. Mind you, practice is needed. I don't use a DA (random orbital)

[John B]

You might be able to do that wiz, but I've seen people destroy 30 years of care and (by default) fairing in 3 or 4 hours as well.( hell one boat was about 70 when the turkey owner took to it with a disc sander.. we thought he was going to sand through the outer skin( about 3/4 inch) )

[PeterSibley]

When I use a disc sander I use the paint layers as a very good guide to progress , you can very accurately guage your progress ....but I suggest learning on a house , not a boat .

[Larks]

I've used a Festool random orbital sander with a vacuum for taking back antifouling before, with good success, but that was provided for the job by another contractor and I couldn't afford to buy one. It was Ok for the antifoul but I don’t know how good a job it would make of the rest of the hull paint.

I've also had far too much time swinging off the end of grinders and disc sanders on construction jobs and steel boat hulls, so I know the damage that they can do when you get a bit tired and careless - very quick to strip paint and timber and anything else - far too easy to dig a great gouge and leave burn marks.

If you ever go to Alice Springs and have a look at the seats in the mall, big 20" square slabs of turpentine from a wharf in Sydney - I made all of those after first grinding back all of the layers of rubbish and weathered timber to clear grain then smoothing them lovingly with a finer grit. They were originally all hand adzed so we wanted to keep much of the character, the 12" grinder with sanding discs did a perfect job of keeping it "dented but smooth". (In the end some clown decided that I'd done too good a job of smoothing them and took to them with a sandblaster to roughen them up again.)

I did the same to all of my 10" hand adzed Jarrah and Mountain ash structural beams from a wool store in Adelaide, as well as my railway sleeper lintels, in my first mud brick house in Alice Springs, (though without the ridiculous sandblasted finish) – painted them with shellac and they looked fanbloodytastic.

I don’t have a disc sander any more, (still have a few grinders) but i get the feeling that the disc sander would be about similar to using my belt sander, just a bit too brutal to be safe on the soft huon pine.

Or am I being a pussy?

[PeterSibley]

I've seen the photos of your house Greg , yes, a lovely job !

I never trusted my Makita until I bought the 7" soft pad ,it's turned a very dangerous tool (!) into something quite gentle .Finer discs than some people use are a VERY good idea too .

Mine is the slow speed version ,a sander polisher .Without going out to look at it , I think 1500 rpm and 3000 .Much nicer to use than the fast ones .It doesn't have soft start though .

[Larks]

I had better have a second look at it then, I'm trying to avoid buying any tools at the moment but it'd seem foolish to not give it a go if you've found them OK Peter. I'll do a bit of reasearch into what's available now, I have most of the current tool catalgues here at work.

[wizbang 13]

makita 9227C ,soft start. Take the handle off, thats for polishing cars. Any boat sanding, keep it flat, moving,and sharp.

[PeterSibley]

I had better have a second look at it then, I'm trying to avoid buying any tools at the moment but it'd seem foolish to not give it a go if you've found them OK Peter. I'll do a bit of reasearch into what's available now, I have most of the current tool catalgues here at work.

I reckon the soft pad ...but not too soft !:D and the slow speed are the trick .$20 at AutoOne and $1 per disc for Velcro .

[P.L.Lenihan]

Thanks for the nice photo tests! However,wizbang 13 has the ticket on this one I think Greg. The paint stripper route is going to produce a ton of garbage,is slow and expensive.What's the clean up routine after all the treatment has been done?Fresh water wash?

Put on the mask, the ear plugs and get yourself into the"zone" for some serious sanding.Make sure there is lots of "juice" and ice for reward afterward! :D:D


Cheers!


Peter

[Larks]

Yes, I reckon I might have to give it a go. I've just been pricing the Makita 9227C, they range here from $385.00 to $440.00, I mostly always buy Makita tools but that's just a bit harsh on my budget at the moment.

However I have had some luck with some of the very cheap Chinese and Korean imported tools, the local Super Cheap Autos store have an elcheapo brand "Rockwell" one that matches the Makite (mostly) for features for $89.00, variable speed, 1200 watts, 180mm - so I might have to start out with that and see how I go.

http://www.supercheapauto.com.au/online-store/products/Rockwell-Shop-Series-Car-Polisher-RS4900-1200W-180mm.aspx?pid=135285#details

By the time I burn that out and replace it a few times within the two year warranty, I should be able to afford the Makita.

[PeterSibley]

Thanks for that Greg , the SuperCheap thingy looks OK ...not that I need one , the Makita is 20 years old and won't die !

[wizbang 13]

The spiral-cool thingy is critical too. The pad that comes with the sander (like the handle) is angled for polishing, not sanding.

[PeterSibley]

Mine's called a sander/ polisher but it seems happy .

[Lew Barrett]

Scraper for the loose stuff, 6 inch DA, 80 grit for fairing. Horrible, but all over in a day or two. Racing sailboats are a bit harder to do.......

Any yard around here is going to make you tent off whatever system you use.

[KAIROS]

Our experience with Peel-Away. Stripped our bottom paint. Maybe 25 years-worth. Yard guys called it 'cow phlegm' which seems about right. It could even be just that......cow digestive juices. Used two complete applications scraping all that would come off after first. Maybe did not put it on quite thick enough first time (used wallpaper brush).....maybe did not leave it cook long enough (12 hours 1st try, 18 hours 2nd). It did not 'peel away' the paint. The paint developed the consistency of bubblegum. Had to use a second scraper to scrape it off your scraper. Could not be 'flung' off.

Used 2 kits, each came in 5 gallon bucket with waxed paper, etc. Maybe 3 gallons of phlegm per kit. This for a 23 foot waterline traditional sailboat hull (photos below). Our main purpose was to avoid having to breath chips, dust, or fumes from all the paint. That was accomplished, but there were a whole different set of issues compared to standard stripping via heat or scrape/sand. Lots of scraping still necessary Tried it on the Cetol on our topsides.....didn't touch it.

One guy at the yard who had the same stripping task ahead for one of his several boats, and already owned a Peel-Away kit, secretly watched our experience. He decided not to use it after seeing us do it. It was expensive and a pain, but a relatively healthy option. I'd use it next time.

[edited: Peel-Away did darken the mahogany under the bottom paint considerably, even though we thoroughly scrubbed and washed the hull down afterwards to remove residue....per directions. Glad it did not get through the cetol on the topsides.....even though we did paint them anyway]

http://www.yachtflyers.com/forum_images/peelaway1.jpg

http://www.yachtflyers.com/forum_images/peelaway2.jpg

http://www.yachtflyers.com/forum_images/jackshoes.jpg

[Lew Barrett]

Great photos, K! That last one...Wonderful, almost art!

[wizbang 13]

The most recent boat I spun off was in a West Indian boatyard. I asked at the office about their protocol for dust.The guy looked at me blankly for 5 seconds, and said "Dis a boatyard mon". I didn't make more dust than the rest of the boatyard, I just made it faster. Point is, can't use my technique most places. I make artificial wind, Hardly get dirty,or hot.

[Larks]

Scraper for the loose stuff, 6 inch DA, 80 grit for fairing. Horrible, but all over in a day or two. Racing sailboats are a bit harder to do.......

Any yard around here is going to make you tent off whatever system you use.

Mine's in my own shed Lew, so only me to upset myself with the dust. I do however have to do both inside and outside, so I'm guessing more than a day or two.

I had made a feeble start up in the bow before injuring myself so am expecting to get back into it with gusto this weekend:
http://forum.woodenboat.com/showthread.php?t=111296

[Larks]

The spiral-cool thingy is critical too. The pad that comes with the sander (like the handle) is angled for polishing, not sanding.

wiz, 'just been looking this up, do you know if they come with a velcro type attachment/facing for the sanding discs? The only one that I could see was for the discs to be attached using a nut and washer, more like a grinding disc than a sanding disc.

http://www.homedepot.com/Tools-Hardware-Power-Tool-Accessories-Sander-Accessories/h_d1/N-5yc1vZ1xr5Zbb32/R-100089981/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

[wizbang 13]

The spiral cool is for 7" (high speed discs, )"green backs" or,sometimes, kind of purple. The velco/self-stick/contac cement, is for the slower speed ,"soft back" sanding. oft backs are 3M,Discit,and a blue one called "ferro".Soft pads are ,off the shelf, 8" dia.

[PeterSibley]

The soft pad I bought spins onto the stud in the centre ,then Velcro discs onto it .

[wizbang 13]

Two different types of sanding. No doubt, the higher speed/hard disc is more suitable to the,mmm,pro,,heh heh.But when you are spinning bottom paint, you have to get it off before it gets hot. Hot paint gums up the disc. That being said, hot paint comes off easily with a sharp hand tool too,albiet slower.Safer?There is not a black and white answer. Environment?/ The environment I care for is the one 4" in front of my face (when grindung)

[wizbang 13]

If you bought the velcro soft pad, then you are obligated to purchase velcro discs. May I suggest you buy the cheepest chineese sander and put the bucks into several softpads and hard backers. The numbers (prices for the tool)you mentioned are numbing.

[PeterSibley]

Two different types of sanding. No doubt, the higher speed/hard disc is more suitable to the,mmm,pro,,heh heh.But when you are spinning bottom paint, you have to get it off before it gets hot. Hot paint gums up the disc. That being said, hot paint comes off easily with a sharp tool too,albiet slower.Safer?There is not a black and white answer. Environment?/ The environment I care for is the one 4" in front of my face (when grindung)

Which is why slow speed is better , less heat and the discs last until blunt , not gummed .I like Velcro ,fast and easy to change discs and easier to use flat .....because the disc is flat right across .$1 per disc is OK if they last , less if you buy by the box from a wholesaler .

[wizbang 13]

Peter, what grit do you tend to use for 10-20 years of anti fouling buildup?

[PeterSibley]

Probably 36 or even 40 ,I prefer to go slowly and use the colour layers as a guide .

[wizbang 13]

Y'know Peter, you may have the best solution for Larks. He has a LOT of paint on there, But your technique is safe .Safe to the boat! Larks, being in your own place is a HUGE advantage. Borrow your neibs leaf blower and hire a youth to hold it behind you as you disc. (musical notes here)disc again, like we did last summer !!

[Larks]

The Super Cheap sander polisher it is - I can buy the 180mm discs here from work at a wholesale price (we have a pretty comprehensive marine store for the workshop) so can take advantage of that. I have a very good face mask and a pretty decent sized industrial fan in my shed and access to some extractor fans here at work that I can borrow. Looks like a fun weekend coming up.

[PeterSibley]

Now for the next thing to borrow from work Greg ....I've used a Racal Airhat for years and it's a brilliant bit of gear .I spent 7 years doing 3 day 8 hour days sanding hardwood and the Airhat was the best bit of equipment in my workshop (complete protection )!...but I think the Triton powered respirator is better and certainly cheaper .If you can beg borrow or steal one , they are so much more comfortable and effective than ANY cartridge respirator , especially in the heat, that there is no comparison .

http://pic40.picturetrail.com/VOL282/9443996/17245530/386750600.jpg

[Larks]

Funny thing is Peter, I was about to mention that I've just overhauled that exact airhat system here this morning so have access to it as well, but I left that out because I thought that'd seem like I was taking advantage of the job a bit much:rolleyes:;):D

[PeterSibley]

You little beauty !! They are brilliant , the only improvement is a small blower outside the shed with a long input hose to the helmet , something I'll have to make up sometime .

You have it all under control !

[Larks]

I have a heap of light weight plastic drop sheet material so thought I might tent her up a bit and run the big fan in one end and an exhaust out the other and out the roller door. I can't actually see a way to attach a hose to the filter/motor housing for the airhat but if I use it the fan and extractor should keep the air coming in reasonably clear anyway.