Smooth 31 year old bottom revealed!

[Jim Walsh]

Kinda sounds like the latest headline from one of the "Scandal Sheets" (if they still exist)
ORION deserved to have a smooth bottom after all these years. I've owned her since December of 06 and I've only applied ablative bottom paint. The previous owners only applied hard bottom paint. Thus I've had to deal with some patches which have lifted over the years. I would usually feather the edges and stand back the rugulation 20 feet.......always looked good to me
This year I decided to scrape it down to the gel coat. Yikes! What a task. I still have a couple days labor left with the scrapers then I'll use my orbital sanders and my 1/4 sheet sander to remove the last vestiges of paint and fair the gouges (oops! dammit!) so the hull (and I ) can rest till spring.
(BTW, I have been using drop cloths to catch all the scrapings and I've collected two full 5 gallon pails full to date, about 100 pounds worth. When I do the sanding I'll be collecting all the dust in my shop vac with a hose connected to the sanders. I've also been using disposable masks to protect my lungs so I'll, hopefully, be around to enjoy the fruits of my labor.)
I'll be applying 3 coats of InterProtect epoxy primer, an ablative bottom coat in some hideous color, and an ablative final coat in a pleasing color. From this point forward I'll only paint the areas where the hideous bottom coat is showing through. This is not something I'd ever wish to do again, but I must admit it's fun.....only because it involves working on a Cape Dory!

[RLW]

Wow! What a workout! Had you considered having her soda blasted? I realize that your muscles and your bank account are both healthier for your choice, but what a task! When you work with the epoxy I recommend working your way upwind as that stuff is NASTY !

[grluecke]

I bought a soda blaster to use on our CD10--she had a leak around the centerboard trunk and I needed to get down to brass tacks...

I just used it that once, I had to rent a rather large air compressor, it was a huge mess (fortunately it was my in-laws' lawn, not mine) and if the working spot was as big as a dime, I was lucky...

I managed to do a strip stem-to-stern about 12 inches wide in the course of 4 or 5 hours, imagine pushing a dime over the entire surface area of your boat!! I wish I had taken pictures, but I finally sold that soda blaster for pennies on the dollar on CraigslList...

Scraping might not be so bad...

SodaBlaster1.jpg (99.27 KiB) Viewed 1035 times

[Jim Walsh]

Wow! What a workout! Had you considered having her soda blasted? I realize that your muscles and your bank account are both healthier for your choice, but what a task! When you work with the epoxy I recommend working your way upwind as that stuff is NASTY !

I did consider soda blasting but I decided the benefit derived from the physical labor involved in my choice to scrape it would be to my advantage. I know it sounds trite but I am enjoying myself immensely.
As far as the smell of the barrier coat goes, I was warned that it pays to have everything laid out and work as fast as is practicable.

[Jim Walsh]

I bought a soda blaster to use on our CD10--she had a leak around the centerboard trunk and I needed to get down to brass tacks...

I just used it that once, I had to rent a rather large air compressor, it was a huge mess (fortunately it was my in-laws' lawn, not mine) and if the working spot was as big as a dime, I was lucky...

I managed to do a strip stem-to-stern about 12 inches wide in the course of 4 or 5 hours, imagine pushing a dime over the entire surface area of your boat!! I wish I had taken pictures, but I finally sold that soda blaster for pennies on the dollar on CraigslList...

Scraping might not be so bad...

That's a very amusing recollection. Clearly if I had your soda blaster I'd be "blasting" till the daffodils announced the arrival of spring. The CD31 has a lot of wetted surface area.....more than I had appreciation for prior to this task.

[Ron M.]

Off season is a good time to do this, you can take your time.
My boat had 20 + years of built up bottom paint - some places 3/16" thick.
I used a 3" wide bent handled scraper with the corners rounded so it wouldn't dig in.
Removed the plastic handle and welded a 2' length of 3/4" rebar to the shank.
The added leverage,( and a keen edge) made the job go much better. I worked sections for 45 minutes at a time or so.
Sanded remaining residue with foam backed disc to 100 grit, prepped and applied barrier coat and ablative bottom paint.
The paint chips were collected on tarps and weighed, 80 + lbs. !
Not a job I want to do again.

[RLW]

A point of reference for the less ambitious...we paid $45 per foot plus $200 materials charge in 2011 to have a 35 foot boat stripped. Note that not all soda blast services are created equally. We did our homework and were very pleased with the outcome. Very fine line at the edges, consistent etching over the entire surface, no burn through, and a thorough clean-up reputation to keep the boatyard happy. We used red as the guide coat and blue for finish coats, and do as Jim suggests: recoat the red as needed keeping build up to a minimum. Hope this helps those with shoulders like mine!

[psjanker]

Jim

I really recommend a full face 3M face mask especially for the final sanding and putting down e2000. Boat bottom "stuff" is nasty and I suspect the long term effects of breathing it into ones lungs is not good. Having purchased one from Jamestown distributors, I find myself using it quite often when doing boat projects.

Pete

[Jim Walsh]

Update.
Progress is still being made! Mother Nature has been very kind so far this season. I am now at the orbital sanding phase. Thankfully, all the work with the scrapers is completed. I have collected 14 gallons of scrapings. Every ounce was hard earned. Rest assured that they will be properly disposed of. My boatyard directed me to double bag (contractors plastic bags) each container and they will dispose of them properly. I think that is a very nice service. I had anticipated having to store it at home for the annual hazardous waste collection. This is certainly more convenient.
Just for those that thrive on the technical aspects I have been using a Porter and Cable 6" orbital sander with 80 grit pads which is hooked up to a wet/dry vac.

[Jeff and Sarah]

It is looking great and I know from experience how big that job is. Might a make a suggestion before you continue? Hit a few square feet of the finished area towards the bow with a pressure washer and see how it holds up. Odds are you are fine, but after doing that full job on Prerequisite, I washed it with a pressure washer and it blasted zillions of tiny bits out of the gelcoat leaving me in a situation where I had to hire a guy with a gel plane to remove it all down to fiberglass (which was actually incredibly reasonable cost-wise). The moral of the story is that it would have cost the exact same amount to have him start with 30 years of bottom paint as opposed to clean gel coat. As this is a job I imagine you never want to repeat, it is worth checking that the gel coat is in as good a shape as it appears. Sanding (in my case) smoothed the hull but the pressure washer was able to open things up that were hidden. Of course, the bottom on my boat looked pretty rough to begin with. There are pictures in a thread I posted around August.

[Jim Walsh]

It is looking great and I know from experience how big that job is. Might a make a suggestion before you continue? Hit a few square feet of the finished area towards the bow with a pressure washer and see how it holds up. Odds are you are fine, but after doing that full job on Prerequisite, I washed it with a pressure washer and it blasted zillions of tiny bits out of the gelcoat leaving me in a situation where I had to hire a guy with a gel plane to remove it all down to fiberglass (which was actually incredibly reasonable cost-wise). The moral of the story is that it would have cost the exact same amount to have him start with 30 years of bottom paint as opposed to clean gel coat. As this is a job I imagine you never want to repeat, it is worth checking that the gel coat is in as good a shape as it appears. Sanding (in my case) smoothed the hull but the pressure washer was able to open things up that were hidden. Of course, the bottom on my boat looked pretty rough to begin with. There are pictures in a thread I posted around August.

I appreciate the suggestion but I'll not be attacking my gelcoat with a pressure washer . Other than a few (or more) gouges I put in it with the scraper my gelcoat is in very good condition. After I get the three coats of InterProtect applied in the spring I will have the Cape Dory version of an icebreaker. I have already promised myself to never repeat this process....and it should never be necessary

[Jeff and Sarah]

The pressure washer in my case didn't damage the gel coat but rather exposed blisters that were smoothed and hidden during the sanding process. I'm glad to hear your gel coat is in good shape though. One less thing to deal with is always a good thing!

I used interprotect as well. I seem to remember them recommending 5 coats minimum though the instructions did say the final thickness was more important than the number of coats.

[Sea Hunt Video]

Jim:

I would be interested in more detail on the "scraper" and how it was used. Any chance you have a photo of the scraper Monthly I use scrapers for cleaning growth from the bottom of S/V Bali Ha'i but I am very sure they are not the same kind of scraper you are referencing.

Thanks.

[Jim Walsh]

Jim:

I would be interested in more detail on the "scraper" and how it was used. Any chance you have a photo of the scraper Monthly I use scrapers for cleaning growth from the bottom of S/V Bali Ha'i but I am very sure they are not the same kind of scraper you are referencing.

Thanks.

Here you go. I cropped this from one of my photos to show the scrapers. One is a "Sandvik" and one came from True Value. One has a straight shank (Sandvik) and the other is curved. You really need both to limit the gouges. They both have a 2 1/2" replaceable carbide blades.
I recommend you never buy one or use it . I hope never to wield one again, unless as a defensive weapon.

[Sea Hunt Video]

Jim:

Thanks. Wow, those look like formidable scrapers (and/or weapons )

Now I can visualize why your bottom had so many "scrape lines". That must have been one heck of a project on a CD 31.

Eventually, in 2-3 years, if I am still the caretaker of S/V Bali Ha'i, I too will want to remove years of bottom paint. I am not sure I will be following in your "scraping" footsteps.

Buon Natale e Felice Anno Nuovo