Bottom coat, remove?

browncbr1

I have an 05 270FV with the 350mag MPI. As you guys know, she's kind of a dog getting and staying up on plane. It has 22pitch props. We have been keeping in the dry racks instead of sitting in the water continually. The bottom coat that is on there was from the previous owner and is a little below the fresh water line. (Seems proof positive this boat was actually kept in salt water previously, contrary to the seller's claim). But, I'm wondering if it would be worth while to strip the hull of all the bottom paint to help improve performance ?? There is a barrier coat as well. Wondering if anyone has had experience with this?
Thanks!

Black_Diamond

Taking it off is an ordeal.  Ideally you have it soda or dry ice blasted off, although most still sand blast.  Either way you are probably going to have to put a bottom coat on again.  VC-17 is a hard coat used by sailboaters, less drag.  

raybo3

Alswagg where they really worth the $$$$$$$. I would have not problem paying for them.... A friend of mine had his 34 foot Silverton soda blasted and it did make a difference in the way the boat performed. It really is amazing how little "stuff" on the bottom can make a "big" difference.

BoatAway

awkwardly laughing at Al's post. wtf

browncbr1

So, just soda blast it and let it ride? Or have someone come after with fresh gel coat? Could I soda blast to get the performance, then do the gel maybe another season? Or would the gel need to be on there to protect the hull from the water on the weekends?

gslpro

I guess I am the only one who thinks $7,500 to remove the bottom paint to gain a "bit" more performance is, well..crazy?????  For that kind of money, I would do an engine swap or upgrade.  Throw a supercharger on the thing.  Yikes!  Have you checked the engine out for compression, fuel flow, cams?  Seems like you need to change boats, upgrade what you have, or learn to live with it being a dog.  I can't picture enough of an improvement from removing the bottom coat.  I hate the stuff, and I have owned boats with and without, and I do agree there is some difference in performance, but not enough to ever justify that kind of cash outlay.  but....owning a boat is the craziest waste of money in many peoples' eyes, so, this comes down to only my opinion.  Yours may vary.  

You mentioned staying up on plane, do you mean at a slow speed, or truly, you can't keep her up there?  You should be running in the mid 30's to 40 I would imagine.  If you aren't getting up there, you have way more issues than bottom paint.  Seriously have that engine looked at.  If she had been in salt, then you probably need a full rebuild or the engine, or possibly a new set of manifolds if they are all junked up.  I had a Chris Craft that went from 50mph+ to 36mph at WOT.  Looked at everything before pulling the engine.  Previous owner had her in salt.  The engine was fresh water cooled, and the was junk.  Manifolds were crumbling in my hands when I took them off.  After a rebuild, back to 50mph.  Sounds more like your issue than the paint.  Good luck.  

Black_Diamond

Taking the paint off and not wrecking the hull (sealing/repainting) is a ton of work. I'd do some hard looking at the engine too.

browncbr1

I wouldn't consider $7500 to remove bottom paint either... a guy quoted $300 to soda blast it all off... I was wondering if it would need new gel, or if it would be ok to let it ride like that.. he said the finishing is smooth, but dull looking... ...   your comment about salt water seems to have some weight here... I realized this boat had been in salt water after I bought it... the motor has some quite a few hours too... I just thought that 4000 rpm would get more than 20mph with a 22prop..   The motor has plenty of power to turn the prop... That's not a problem...  I can run up the rpm really high and it can scoot across the surface just fine..., Granted, I haven't had it on smooth water yet... I was beating through the waves and wind on erie... this weekend, it should be smooth and I'll do some more testing...  The last time I was out, it just seemed like keeping at a comfortable cruising speed (~23-24mph) would be running the motor too high..   I'll test this weekend on smoother water and make note of rpm and trim settings, etc.. 

TikiHut2

My '04 270 doesn't have bottom paint and has lived it's entire life in the Gulf but rack stored. In Aug 2011, at 7 y/o, just before we bought her and after a through survey it got new risers and manifolds/plugs n wires/fuel tank (mfg defect) / impellors/ regular annual service to the engine, drive and genset......basically what every boat deserves after 7yrs (except a fuel tank hopefully).

Ours runs like a champ and I'd say that it's because she has been well attended to her entire life (and I've learned a few tricks that this boat needs re trim and weight distribution). GSL has a good point that if your 270 is lacking in performance it's either needing some regular attention or your expectations are too high for an RV of a boat. If you think it might be the bottom paint, get a respirator and haz suit on and take an hour to hit it with sand paper to knock the texture off. It's really very simple to get it somewhat slick unless it's 14 layers thick (doubtful) which you should strip off later. If ,as you suspect, it was a saltwater boat then the bottom paint is probably ineffective in your region anyway.

Otherwise unload the weight from boat, taking everything off that you can imagine including emptying holding tanks and a light fuel load. Move other items amidship or forward, change your fuel filters and run it with a half filled tank of something non-ethanol and high octane. If it won't (relatively) jump out of the hole (assuming you are trimmed correctly running in neutral seas and weather conditions) in 6-9secs then there's more to it than bottom paint as GSL said.

Good luck. Mike

browncbr1

Hi Tikihut,

I just posted on another thread asking you what pitch prop you have.. mine are 22's... The motor absolutely has no problem turning them and getting out of the hole is no problem.. I was just thinking that I'm running kind of high rpm's for a comfortable cruising speed of about 23mph... it sounded like you could do this at 3800rpm, while I'm running higher...  albeit, seas were rough and windy last time..   like i said above, I will take it out again this weekend on smoother waters with little wind.. I'll note all rpm and trim settings and come back and post results..   I may hit the bottom with a random orbit sander one of these days just to smooth it out a little bit like you said..

browncbr1

Well, I went out on Sunday. 1/4 water tank. 1/2 fuel tank. And two of us until the in laws unexpectedly showed up uninvited and insistant to go out with us. Unfortunately, they are about 350lbs each. They also preferred the back seat at all times. Wind was 10-15, Bimini top up, tabs up, and cruise @ 3800rpm was 25-28. Water was not smooth. Maybe next weekend will have a clearer picture.

ithacarink

I also have a 05 270. 350 MPI mercruiser. Those numbers (3800 rpm and mid 20's) sound about right on to what I get. Don't know my pitch or drive ratio off hand but can only presume it is "stock", whatever that is/was. I do have bottom paint, Interlux VC17, which is very smooth. She certainly isn't a speed boat but also stays on plane fine for me. Let me know if you want me to try and match some of your test parameters, would be interested in how they compare.

browncbr1

Hi carink,
Thanks for your comment. I imagine it would be difficult to compare apples to apples, as I will likely never see the same conditions on Lake Erie as everyone else on inland waterways. The bottom paint on mine is from the previous owner, so I'm not sure what kind, but it looks pretty beat upon places and doesn't look increadibly smooth. I was planning to eventually hit it with a random orbit sander to Atleast smooth out some of the rough areas that developed from being put on and off the trailer.

gslpro

Okay, I found an old boattest.com review of the 270, from 2005.  Their cruise number was 26.5 mph at 3500 rpm with a single 260hp gas merc.  Sounds like you are in the ballpark.  Remember, their numbers com from a brand new boat with no bottom paint and ideal conditions onboard.  

browncbr1

Nice find on the baseline. Yea, I think a lot of it is just the typical conditions on Erie and rough bottom paint. I just would like to easy up on the motor a little and stay nicely on plane to find a sweet spot. I just need to get to know her better

Michael T

Apparently there is a new "glossy" barrier paint available that is very durable and very slick. I was told that if I had it done on my new 2013 EC 310 before there was any osmosis blistering the whole job - ablating, prepping and epoxy coating would be about $4,000.00. I didn't ask any questions as I had just received my new boat the day before and wasn't thinking of blasting the gel coat off at that point. But, if there's any interest I would be happy to contact the gel coat guy that my marina brings in to get the info. My personal opinion is that re-gelcoating a hull is a waste of money as it will osmosis blister even faster than the original gel coat. If a new bottom is desired go with an after market bottom coat.MT

browncbr1

thanks for the info michael,.. Yea, I think I might just have the bottom paint redone using a good quality hard paint.  There is already a barrier coat on there, so I guess I just need to get it smoothed up a little bit..