Vactanning the hull

[Bargebuilder]

10 minutes ago, blackrose said:

 

The other reason of course it's that epoxies are more technical paint systems. As well as good steel preparation (from new or if changing from bitumen) one needs to take care to mix epoxies properly according to weight or volume as well as pay attention to minimum and maximum overcoating times according to ambient temperature. 

 

Most boat yards can't be bothered with all that and would simply rather just slap on a couple of coats of bitumen. It keeps their expensive dry docks, slipways and cranes busier too!

What you say is correct, but more so for some epoxy coatings than for others.

 

Most certainly, a rough, clean steel surface is necessary to get the best out of these coatings, but Chemco will be able to advise and recommend surface tolerant primers under some circumstances.

 

The one I used came as a big tin and a small tin and all I did was to tip into another container half of each tin and mix the two with a electric drill driven paint mixer for half a minute. I got through 16x 5kg tins and had no problems with mixing. Other makes of paint may be more difficult to mix possibly.

 

There is no maximum overcoating time for Chemco glassflake as you can overcoat it 10 years later without further preparation or abrasion and doing one coat each day worked very well for me. 

 

Other epoxies can have minimum/maximum overcoating times: I understand that epoxy tar does, so best to check before application.

 

Airless spray application is easiest, but not many DIYers will have such equipment. I used a bog standard paint roller and roller tray which worked brilliantly. 

 

 

[David Mack]

13 hours ago, Bargebuilder said:

 

Also, Chemco is a commercial company, mainly selling its product by the lorry load to water companies and other huge organisations, so it's web site reflects that. However, the sales team and technical advisor are great and very happy to sell in small quantities when asked.

I was wondering how one acquired Chemco products as a DIYer needing what in their terms must be small quantities - the marine case studies I looked at are all about oil tankers and cruise ships!

 

I'm on the lookout for suitable products for painting bilge areas - engine room which will no doubt be subject to bilge water and oil/diesel leakage, dry (hopefully) bilges under the cabin and a wet bilge area under the front deck. I should be able to get these areas grit blasted so it seems to be worthwhile using a coating which should last a bit longer than ordinary paint.

[Bargebuilder]

It was a few years ago now, but I spoke to a chap called Manny if I remember correctly and he said they were delighted to sell just one tin if asked and they had no issue at all with satisfying my order. 

 

They do epoxy coatings that are for potable water and suitable for coating the inside of steel water tanks. They also do ones suitable for the inside of diesel tanks. 

 

The outside of our hull was blasted, but I had to prepare by hand with wire brush and cup brush the inside of our tanks, but the surface tolerant primer supplied worked well even on surfaces with relatively poor preparation. My advice is to be guided by their technical chap and you won't go far wrong.

 

My barge was actually more saleable having been glass flaked, as the buyer recognised that the coating would save him money compared to the other barges that he'd viewed that would need blacking every three years. When eventually the time comes for you to sell, do as I did and include in the description the benefits of the coatings you have used.

 

I hope the job goes well.

 

 

The stock colour is grey, although they can provide any colour if the order is large enough. If your order is too small, simply protect the steel with the glass flake coating and paint over it with any cosmetic colour you like.

[Sea Dog]

14 hours ago, TheBiscuits said:

 

Nah, hours ago!

If only I hadn't done it weeks ago!  

 

(Actually, I'm thinking Vactan will be fine. It was good under bitumen and everywhere else I've used it. We'll see though, eh?)