Jump to content

Blasting and blacking


Featured Posts

Interzone is a 2 pack epoxy cozting by International.

 

Not sure what Intertuf the top coat is, presumably Intertuf 16?

 

How long does a 2 pack blacking usually last, given my bote has had little use and stayed mainly in a marina until I got it (700 engine run hours in 7 years)?

 

When the times comes for re-blacking, I will get it re 2 packed, but this time in a black colour, so that it doesn't need overcoating in bitumastic blacking to get it to look black :)

 

Presumably I can tell if the original 2 pack needs redoing when the bote is out of the water, because it will be coming away from the steel?

 

Anyway, thanks for the advice so far Blackrose.

Link to comment
Share on other sites

Debdale do a good job but I a year later have still not received any paperwork ?

 

I got paperwork from them when I picked up the boat - or at least an itemised invoice.

 

Our hull was gritblasted & epoxied about 7 years ago now and at the survey when I bought the boat, the surveyor was very pleased with it. I would definitely have it done again.

We just had our cabin gritblasted at Debdale and while some grit did get in, it was cleaned up by running the hoover round. I'd recommend Debdale as they stuck to schedule and were communicative and professional about the whole business. Sure, it cost more than trying to do it myself, but for me, personally, I don't have the time or expertise to do it myself so I'm happy to pay someone who does.

Link to comment
Share on other sites

A few photos of my boat in the drydock:

 

After grit blasting.

CAM00525_zps221399a5.jpg

 

First coat: Jotamastic 87 aluminium

CAM00529_zpsfe9788ed.jpg

 

Who was it that said widebeams have short swims? It certainly doesn't feel like that when you're under there painting it.

CAM00531_zpsf2de3e7e.jpg

 

Second coat Jotamastic 87 aluminium (red tint)

CAM00535_zpsf94ffa4c.jpg

 

Third and fourth coats Jotamastic 87 black.

CAM00553_zps74b09e55.jpg

 

I had this 10mm plate welded between the stern gland bilge pump sump box and the front of the skeg, which might give the boat a better chance of riding over an obstacle like a sunken tree trunk and should protect the skeg a bit better.

CAM00544_zps7447b684.jpg

 

This is the bottom of the rudder tube Assuming it's this diameter all it's length I guess there would have been no benefit in painting it as it's a tight fit with the rudder stock?

CAM00543_zps612489d7.jpg

Edited by blackrose
Link to comment
Share on other sites

Interzone is a 2 pack epoxy cozting by International.

 

Not sure what Intertuf the top coat is, presumably Intertuf 16?

 

How long does a 2 pack blacking usually last, given my bote has had little use and stayed mainly in a marina until I got it (700 engine run hours in 7 years)?

 

When the times comes for re-blacking, I will get it re 2 packed, but this time in a black colour, so that it doesn't need overcoating in bitumastic blacking to get it to look black smile.png

 

Presumably I can tell if the original 2 pack needs redoing when the bote is out of the water, because it will be coming away from the steel?

 

Anyway, thanks for the advice so far Blackrose.

 

Once the boat has been pressure washed you'll be able to see what sort of condition the paint is in. If it's still sound you can just abrade the surface with say a 180 grit paper (get the paint manufacturer's advice), brush the dust off well and then paint a couple of coats of the same stuff on top.

 

How long it lasts is dependent on a few variables, but I'm hoping mine lasts at least 8 years - possibly longer.

Link to comment
Share on other sites

Interesting photo's

I am very surprised that your skeg had such a blunt profile to it's leading edge, I would have expected it to be "flowed" in for protection. Your extra bit of plate looks to be a good idea. Does the bilge pump sump box have a contoured leading edge or is that square as well?

Link to comment
Share on other sites

Once the boat has been pressure washed you'll be able to see what sort of condition the paint is in. If it's still sound you can just abrade the surface with say a 180 grit paper (get the paint manufacturer's advice), brush the dust off well and then paint a couple of coats of the same stuff on top.

 

How long it lasts is dependent on a few variables, but I'm hoping mine lasts at least 8 years - possibly longer.

Thanks Blackrose, the boat was last out of the water a year ago for the survey and was pronounced OK, so I will get it taken out next year, get it pressure washed and then see what needs doing. Worst case will be that it needs blasting back to the steel and re epoxying.

Link to comment
Share on other sites

Just for info, Debdale charge £24 per sq m plus VAT for blasting, £15 per sq m for epoxy coating. I guess a w/b would come out at £6k or more but it's academic of course. If it seems expensive look at the harware they have to keep the mess to a minimum:

 

debdale_zpsxpb1jziq.jpg

This is the extraction unit at the back of the bay where they do the blasting. There's not a trace of grit or debris outside.

 

A sort of inflatable tent sits on top of the boat cabin which is sealed and pressurised to suck any stray dust/grit out. It's a very impressive set up, if not the easiest place to get to.

 

 

Link to comment
Share on other sites

I need to get onto a barge grid to inspect the bottom of Sabina as soon as I am fit enough. I then will decide what needs doing (now about 8 years or so from grit blast and Interzone)

I think that if it needs taking back to bare metal I might go for the water blast method. I will deffo be using Interzone 954 again though cloud9.gif

Link to comment
Share on other sites

I asked him, he said it's glass.

 

 

I can get around this boat by myself in about four hours. One coat per day, 24 hours between coats and 24-48 hours before immersion. Should be ok, but if anyone wants to help I'm at harvington on the Avon.

 

The grit blaster finished at about 2.30pm today but even though he blew most of the grit off the boat with a compressor when he finished, it still took me about 3 hours to clean up. So I didn't manage to get the first coat on today. Hopefully it won't flash rust overnight, but the paint is supposed to be tolerant of flash rust.

When you say it took 3 hours to clean off was that the grit blasted area ,did you have to use a solvent to clean it or it ok to paint straight over after being blown off .How clean is the area that has been blasted .

Link to comment
Share on other sites

 

Once the boat has been pressure washed you'll be able to see what sort of condition the paint is in. If it's still sound you can just abrade the surface with say a 180 grit paper (get the paint manufacturer's advice), brush the dust off well and then paint a couple of coats of the same stuff on top.

 

How long it lasts is dependent on a few variables, but I'm hoping mine lasts at least 8 years - possibly longer.

Those anodes might not last 8 years though Mike, they looked half depleted.

Link to comment
Share on other sites

Interesting photo's

I am very surprised that your skeg had such a blunt profile to it's leading edge, I would have expected it to be "flowed" in for protection. Your extra bit of plate looks to be a good idea. Does the bilge pump sump box have a contoured leading edge or is that square as well?

It's square, but it's made from 10mm plate and it's extremely well welded so I don't think there's any danger of damaging it.

When you say it took 3 hours to clean off was that the grit blasted area ,did you have to use a solvent to clean it or it ok to paint straight over after being blown off .How clean is the area that has been blasted .

No, it was the entire boat that needed sweeping. The grit was everywhere. The blasted areas just needed brushing off and then I painted straight on. It wasn't a dusty substrate. I did ask Jotun about spirit-wiping the surface with the correct thinners before painting, but they said that spirit- wiping just moves dirt around and doesn't remove it.

Those anodes might not last 8 years though Mike, they looked half depleted.

Half depleted... then they should last another 10 years. (That's how old they are.)

Edited by blackrose
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.