Barrier Coatings are they it worth it?

[ColRon]

HI all,

This past weekend I moved Escape Plan 40 miles downriver to get her pulled out onto the hard and get her bottom paint redone. When I bought her just over two years ago and had her surveyed we noticed a handful of blisters but nothing major that would cause concern. She was pulled yesterday and they started removing the old bottom paint. Well, they found some old blisters that weren't properly repaired in the past. The slurry blast was actually popping some of the old repairs off and others it was loosening. It appears that whoever repaired them for the PO had not removed all the bottom paint, so the edges of the repair materials was feather over the old paint. So now I have about 50 old repairs to re-repair.

So bottom paint and blister repairs are estimated to run me about $5300. The shop is also recommending that I put at least three coats of Interlux 2000E on after the repairs to prevent re-blistering at an estimated cost of an additional $2500.

Is the barrier coating worth the expense? My understanding is that a barrier coat still won't actually prevent any new blisters, but will reduce them. What can I expect if I do and if I don't put on the barrier coating? I have an old receipt where a bottom job was done before and supposedly an epoxy barrier coat put on then, but it is from 10 or 15 years ago.

Presently we are proceeding with lets get the blisters repaired first and then revisit the issue then to determine if we barrier coat or not.

Your thoughts and advice are appreciated.

Thanks in advance...

[bud37]

Will your people be cleaning right down to the original gel, then how long will they allow for drying the blisters ? My understanding of the interlux was that it needed to be applied to a certain thickness, or at least it was years back, and at that time I think we had to put 4 coats to get it, maybe different now though.

I think if you are planning to keep this boat for a long while, then it will pay to repair it properly. the barriers work if applied correctly following the makers instructions with no short cuts.

[ColRon]

Bud, they are expecting a couple of weeks for drying and will be checking it with moisture meters and yes, their going to clean down to the original gel is my understanding.

[Cooler]

Ron, that is a big job. I assume the boat is in the water basically year round? You may want to get in touch with Interlux. They are very willing to offer guidance on projects like this. The barrier coats do work, and you have the correct understanding. Ask Interlux if they would recommend Epiglass as a filler coat as a first layer. Then the 2000E, then the bottom paint. May reduce the number of 2000E coats, and provide better protection. What is your shop using for bottom paint. You may want to consider the Offshore formula, which is expensive, but will last 4 times longer on the hull. Again, ask Interlux. They would have a rep in your area that works with your shop. The majority of that expense is labor, so the product expense variation should be reasonable. The Interlux rep informed me about the Offshore formula last season, but is reluctant to push it with dealers because annual sales of basic formulas. Good luck. er

[Cooler]

Interlux has done a lot in terms of reformulating over the past few years. Ecological regulations force their efforts. er

[Viper]

Oh boy, I really hate seeing substandard repairs, it gives the industry a bad name. If you can't do it right and for the cost of what ever it takes to do it right, then just don't do it at all

I'm pretty sure I posted the correct process to do a proper bottom job to deal with osmosis and barrier coating in a previous thread. IF done right, you'll have a hull that's better than new. Should you put on a barrier coat? Well, consider this; the gelcoat is porous believe it or not, and while the fiberglass under the gelcoat will keep water out, epoxy is a much better water barrier and a much stronger one. There is a minimum recommended finished thickness that one should strive for and I don't think it's achievable with three coats though I don't know how they're planning on applying it. I've always done at least 5 coats rolled on though a friend of mine in the business says he can achieve the same with fewer passes by spraying it on instead. Tip; to ensure complete coverage, alternate colours (white, grey) for each coat so you can tell you're not missing a spot. AND if they don't get all the existing bottom paint off first, they shouldn't even begin doing anything else.

Will a barrier coat prevent blisters from appearing in the future? NO. Blister/osmosis is a complex process dependent on several variables however most people think they're only due to water ingress and that's not always the case. Osmosis can start/originate within the glass mats as a byproduct of manufacturing and curing (chemical reaction), and can manifest many years later. You can epoxy the bottom and still have blisters appear after the fact, especially if you didn't get all the superficial ones ready to pop that are just below the surface. This is why the service provider should always educate the customer prior to performing the job or they may be setting themselves up for a disgruntled customer if they are led to believe that a barrier coat will prevent blisters from appearing later.

For a proper bottom job, repairing blistered areas, prepping for and applying epoxy putty to the entire bottom depending on severity, sanding/fairing, then applying a barrier coat and bottom paint is an extremely labour intensive process. That up my way is usually at least $10K (Canadian) for a hull around 36'. Anything less than that is usually a pretty good indication that corners are being cut either in the procedure or materials. The proper materials are not cheap, nor is a good technician with a conscience.

If the shop has the right equipment, they can vacuum bag that hull dry in no time.

[Cooler]

Viper - very well said and explained. +1 er

[Viper]

PS; if you're going to pay big bucks for that type of job, you have the right to require that they indicate in writing ALL the steps they will take in the process from beginning to end, and ALL the product they'll be using and their brands. I'd be curious to see that.

[ColRon]

Source of the post PS; if you're going to pay big bucks for that type of job, you have the right to require that they indicate in writing ALL the steps they will take in the process from beginning to end, and ALL the product they'll be using and their brands. I'd be curious to see that.

Thanks Viper, that’s good to know. I will keep that in mind. For the time being we are going to get the blisters repaired first. He said he was estimating high on that because he didn’t want to give me a number and then it come in higher than that.

I have bottom jobs done before, but this is the first time I was ever advised to have a barrier coat applied. But this is also the first time I have used this shop for a bottom job. They’ve done other work for me in the past and have always seemed reasonable.

[Viper]

For what it's worth, if you're not proceeding with all the work to include a barrier coat because it's just not in the budget at this time, keep in mind that blisters unless sever in size and deep, are not a structural concern. In the long run, it will be cheaper to have everything done at once rather than re-prep for the balance of the work at a later date; removing paint again, etc. The biggest problem with blisters is that they are wrongfully perceived as a major problem with the hull, especially to an uniformed buyer. It's more of a cosmetic concern than anything. Unless it's severe, I wouldn't stress over getting it done right away if budget is a concern at this time.