“PERMATRIM”

[Connie Fisher]

There have been quite a few threads about “PERMATRIM”.

After reading about this item, I decided to order one for our 19’ CD w/ 90 HP Honda.

I have a good relationship with Winegar Works Marine Outfitters in Guttenberg, Iowa, who have operated a marina and marine services here for well over forty years.

The “genius marine mechanic”, Eric does a marvellous job and his shop works on all types of marine challenges.

So, I took the 19’ and the just received “PERMATRIM” to Winegar’s for Eric to install.

Being polite but also being comfortable with our relationship, Eric grinned and said “Ron this is snake oil, your boat already has trim tabs, how do you think this will help anything”?

A good question that I obviously could not answer.

Eric also added that Mercury Marine does not endorse or recommend any of the “gismos” that are bolted onto motors lower planing plate.

Woulden't it stand to reason that if “gismos” that are bolted onto the motors lower plate really worked or were an asset to performance, that marine motor manufacturers would already have addressed this feature with “gismos” of their own to add on?

I’ll return the “PERMATRIM”.

Regards,

Ron Fisher

[hardee]

Ron,

Your “genius marine mechanic” may know what he is doing, and what he says makes sense.

I am not a “genius marine mechanic”, or not even a mechanic at all. I don't have a Ph.D. in physics or engineering either. I don't have Permatrim(s), either. And I have read a good share, (most) of what is on here about them.

AND/BUT, to me they make sense. The physics principals make sense, and most what I have read about them here makes sense to me. I trust many of the folks here who post them, and I believe that they are posting from their interest in sharing knowledge, not that they are trying to sell something to make another buck for themselves. (Not that making a living is a bad thing but selling snake oil to cure hives, gout, measles, hernias, and all cancer is.)

From the experience of friends who have them, I have decided to try them too. Haven't done it yet, other priorities first, but they are on the list.

Your “genius marine mechanic” may be onto something, when he speaks of the OEM adding it if it works. Yup, and maybe so, but there may be other factors that inhibit that. Added cost, work better in some applications than others, some sort of liability, packing and shipping modification requirements or a dozen others I don't know.

If it were me and I had ordered them already, I'd have the installation done, and see if I liked the difference or not. It could always be taken off.

JMHO, YMMV, AGAGNS (And Get A Good Nights Sleep )

Harvey
SleepyC

[dutch123]

C dory owners who already have permatrims will agree that they are an excellence addition and very helpful to lower the bow in the chop to reduce pounding. Getting on plane at 10 knots is nice too. There is a small reduction in top end speed and caution is needed when running in a following sea( don't trim down too far or bow may dig in and cause broach) Using permatrims on twins also has the added benefit of being able to trim laterally as well.

[TyBoo]

I was once a genius on this subject myself. I tried a Doelfin for a short while and found I was better off without it. On my next C-Dory I needed a little more control than my inadequate trim tabs could provide and tried the Permatrim. After a short time figuring out how best to let it work and a little longer time letting go of my stubborn belief that it was a gimmick I found myself getting 3-5 more MPH for the same or less fuel use and also was able to let my trim tabs be much more useful for lateral trim. I am betting your mechanic is basing his observation on the traditional hydrofoil and has never tried a Permatrim.

My theory is that trim tabs push the bow downward whereas a hydrofoil lifts the stern and allows the bow to drop down. The hydrofoil effectively makes the whole boat ride higher in the water on plane which makes for less resistance and better efficiency. Big difference in physics and a combination of the two will provide many more options for making the hull do what you want it to do. Outboard manufacturers make the motors like they do so they will best work on the most hull styles.

[Jazzmanic]

The first year we had C-Dancer, we installed a Permatrim on our Suzuki DF70 and loved how it got the bow down with a small touch of the button. When we decide to move up to a DF90, we added trim tabs without a Permatrim. I was not satisfied with the level of trim it provided the boat, it didn't have nearly the effect as the PT for getting the bow down. Therefore, halfway through that season I added the PT and haven't looked back since. Now I use the trim tabs primarily to adjust the lateral trim of the boat to compensate for uneven weight distribution etc. The PT makes a huge difference in adjusting the bow/stern trim with very small incremental adjustments, not just an opinion but real world experience. Not snake oil at all IMHO.

[localboy]

I'm still on the fence myself...

[Da Nag]

[Connie Fisher]

I really appreciate the intelligent, mature exchange from practical experiences with “PERMATRIM”.

The comments from practical experience are well received and quite helpful since this subject has really been “beat to death”.

It’s sometimes difficult to separate practical experience from emotional attachment.

I trust my “genius marine mechanic”, Eric’s expertise, however at the same time understand that Mercury Marine may “for many reasons” actually need to take a neutral or mute position with anything that potentially will be bolted to motors of their manufacture, same with other motor manufacturers.

To really make a objective conclusion about “PERMATRIM”, I’ll consider having it installed and see what happens.

Thank you for the discussion.

Regards,

Ron Fisher

[C-Pup16 in Los Angeles]

You drive your boat, not your mechanic. He may be sincere adn trying to be helpful, but I'd check it out if possible on another CD with PT to "feel" the difference. I have the bat ray thick plastic wing style fins that help a lot with trimmong a 16 ft CD. I feel that I might get better mileage and experience less cavitation wear on the prop with the thinner metal PTs .

[Sea Wolf]

Ron-

Here's the story on Permatrims and the CD-19, specifically, IMHO:


The CD-19 hull is the same as the CD-22 hull, just with 3 feet removed from the stern.

When Bill (Da Nag) bought the first CD-19 produced, he found that the hull porpoised at speed.

He eventually added both trim tabs and a Permatrim.

The boat apparently needed both the Permatrim and the trim tabs to be stable.

These two devices ("Gismos" if you will) made up for at least some of the missing 3 feet of hull that left the boat unstable at speed (on plane).

The Permatrim works that way on all boats, effectively lengthening the boat's hull with it's extended lever arm at the rear on the engine's anti-ventilation plate.

If I had a CD-19, I'd make my own Permatrim/hydrofoil (I've done it before), make it extra large, only limited by how much stress I thought I could get away with on the anti-ventilation plate, and also add the largest Bennett trim tabs I could, perhaps even extending them in size, particularly aft.

That's my story and I'm stickin' to it!

(With apologies to Bill for telling his story for him (as I see it.)

Hope this helps!

Joe.

[Writer_Ron]

[Spike]

Ron
I don't know what you paid for your permatrim but mine cost $100+ and I can think of alot better uses for my money. To me it is just not worth the money. IMHO. I will keep it on now that I have 6 nice holes in the cavitation plate. I can do every thing the PM can do with trim tabs shifting weight forward. Like I said just IMHO.

[westward]

my practical experience with permatrims was very good on my previous 22 angler, and I've already installed one on the brand new honda 50 of my current 16 angler. Both hulls were designed around lighter 2-stroke engines and tend to be stern-heavy with 4-stroke installations, dual batteries, etc. I was looking for hydraulic lift at the stern and the Permatrims have helped noticeably. On the 22 (twin engines) I omitted trim tabs altogether because opposing the permatrims could largely achieve the same lateral trim effect. Bow down (and thusly a smoother ride in chop) is enhanced. Ditto the other comments on need to trim up in following seas. Before installing on the new Honda 50 I called Honda directly and they gave me the go-ahead; they knew of the product, didn't endorse or dissuade, and assured me that installing wouldn't affect my warranty. It is inarguably difficult to touch a drill bit to the anit-cavitation plate of a brand new motor! Best, Mike.

[Robbi]

I had a CD 19, and as Seawolf explained, the 19 and the 22 are different birds. From my experience, a 19 gains the most from having a Permatrim. Next in line is the 16 cruiser.

If I had a 19, it would have one, even with trim tabs(which I had). It was the best addition to the boat I made. Even more beneficial than the trim tabs.
On the 19, not snake oil and not wasted money.

Robbi

[Connie Fisher]

Update!

Thank you, Harvey, Reel Action, TyBoo Mike , Peter, AU KAI, Da Nag, C-Pup, Joe, Muse, Chuck, Steady Eddy and Robbi for your comments.

After reviewing and considering all your comments, it would seem prudent to install the “PERMATRIM” and make my own judgement/s about this product.

I believe that “Robbi’s” comment that “the 19 and the 22 are different birds” is “spot on” since this just purchased 19’ is very different than the 22’ and 16’ that we previously owned, I’m hoping that the “PERMATRIM” will “tame” some of the 19’ characteristics previously mentioned , only one way to find out.

I figure when “TyB00 weighs in, also with Sea Wolf’s explanation about “Da Nag’s” 19’ CD experience and then others that are on the fence about this product, I’m going to have the “PERMATRIM” installed and see what happens.

Otherwise, “I would always wonder” and have to accept someone else's (proven or unproven) assumptions, conclusions or fears.

So, I dropped by and visited with Eric and we together will install the “PERMATRIM” tomorrow morning.

I noticed “Da Nag’s” little jab about diesel, which is in my mind no different than this discussion, unless or until someone does their own “testing” and/or only listens to someone's else's reasoning, theories or fears, then what is the point in any discussion or sharing of information?

OBTW, I did receive return authorisation from Shipyard Island Marine (where the “PERMATRIM” was purchased), my return request was handled very professionally and courteously.

And Chuck, thank you for your candidness, but I have already purchased and received the “PERMATRIM” ($163.84 which includes shipping), and would have some expense to return, so why not go ahead have it installed and see for myself if it will help our 19’ CD’s performance (I’ll report back).

So, “if” this works out “good for us”, if it does not, I’ll sell the “PERMATRIM” on ebay or to one of you that wants one at a reduced price and again “good for us”, a win win.

Objectively speaking, if I don’t try this product first hand, "I would always wonder” wouldnt you?

Again, "thank you all" for your comments.

Best regards,

Ron Fisher



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