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Uniflite blister woes

Old 04-19-2019, 09:22 AM
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Default Uniflite blister woes

Hey all ... well, I've progressed from looking at and assessing Uniflites to owning one ... a '79 42' Uniflite Double Cabin Sedan with DD 6-71N's and Twin Disc MG506's.

I have lifted this boat twice ... once for a powerwash and an hour or so of inspection on 24OCT18 (at that juncture, I aborted a pre-purchase survey and was going to walk away from the vessel due to prolific bottom blistering, however, the owner eventually made price concessions that incentivized me to purchase the vessel as is at the end of February, 2019) and then I lifted her again the other day on 17APR19. Following power-washing, blocking on-the-hard and completion of a post-purchase insurance survey on the 17APR19, it was clear I was going to have to be careful with the handling of bottom prep (vis-a-vis the proliferation of nickle to quarter-sized blisters, most all with a 1/8~" high white styrene excretion mound evident) in order to avoid going down the rabbit hole of extensive blister repair. My thought was to knock off the styrene excretions and sand the bottom carefully prior to a bottom re-paint without puncturing / opening up blisters ... and simply live with the condition ... all my reading (I found David Pascoe's articles very informative) on the subject suggested I'd spend an awful lot of $ and largely be wasting my time and money, as these post-August, 1974 fire-retardent resin-origin blisters reportedly typically come back or re-appear elsewhere anyways. With the relatively thick (>3/4") hull bottom layup used by Uniflite back in the day, I convinced myself to not be overly concerned about the blistering I had seen on 24OCT18, structurally-speaking.

Anyways, despite my specific bottom-prep procedural sanding instructions to the boat yard manager at my PNW marina (the chandlery / mechanical services / boat yard operators leasing from the PTRMarina owners have, what I suspect, is becoming a more prevalent policy: only they can power-wash and bottom sand vessels blocked in their yard, due to environmental / bottom paint residue containment considerations ... as a DIY owner, I was told I was not allowed to perform any bottom prep), he used a younger person (whom I did not meet or brief and know little about, yet) to machine-sand the vessel bottom and the results are that a great many of the blisters have been opened up ... with the raised portions / tops of the blisters removed, and, in most cases, a dark / black liquid [undoubtedly styrene suspended in water] still present inside them when I viewed the vessel yesterday mid-afternoon. These opened blisters are typically about the size of quarters or smaller and have a thin (gel coat [if there was any left, or, previous repair / paint compound layer(s)] & skinout mat?) delaminated periphery ... so, on a downpour of rain-type day, when no sanding was supposedly going to occur, four hours of machine-sanding were logged on my vessel before I could intervene ... now I'm faced with some decisions about my next course(s) of action.

I could finish up with exterior zinc replacements and go back in the water, as is, the bottom to be dealt with again down the road at a different (perhaps Canadian) yard where I have more control, more time, reduced fixed yard costs and a more competitive pool of experienced contractors ...

Or, am I inviting big trouble by leaving these opened blisters as is? Must I deal with them, even if only to a certain extent? And if the latter, what should my blister-site prep goals be ... any insights on procedures / materiels would be appreciated, as I will have to deal with this specific boat yard manager and his staff and effectively communicate what I want done, looking forward.

Hopefully my fellow THT'ers can offer some targeted advice ... thanks, FFF

P.S. I may have legal re-course grounds to consider at a later date, however, right now I'd prefer to focus on the task at hand ... also, for those who want to offer advice but want / prefer to see pictures, I'll be getting some today I expect.




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Old 04-19-2019, 09:58 PM
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check out the gelcoat peeling process also goog search for uniflite blister problems, tons of info
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Old 04-20-2019, 06:28 AM
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FFF- you now know why Uniflite went away in the early 1980's. IMHO the only way to fix the issue is to do as Chaps said. Peel the entire bottom, let the boat sit to drain and dry and relaminate the bottom. As Chaps said there is tons of info on the web on fiberglass blisters and the problems with Uniflites in particular. The yard has taken away your flexibility on when to have this done.
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Old 04-20-2019, 06:36 AM
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Get in touch with Hull Tech in San Diego, this all they do
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Old 04-20-2019, 11:50 AM
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Thank guys for stepping up, helping out and the advice offered ... so, after further investigation (and discussion with various folks at the PTRM yard, knowledgable to varying degrees), the blisters are all filled with a styrene? (blackish-hued) watery suspension (not goopy or gooey at all) and are beneath only a thin layer of gel coat and / or whatever previous repair compond(s) / barrier coat(s) may have been used over the course of this vessel's 40 year life (the previous owner couldn't remember much but did allude to prior bottom blister repairs having been done ... the underlying f/g layup material is seemingly uniformly hard and healthy-looking, not whitish or opaque and not punky or pickable. After further consulation last night with my insurance surveyor from the 17th, a gentleman named Matthew Harris from Bellingham, WA, and given my circumstances, rather than try to go down the proper repair path where I am currently on-the-hard, I believe I'll simply open up all the blisters with a hard plastic, modified putty knife / scalloping tool, give them a couple of days to dry out, get the yard to sand / fair the surface flush to the extent possible (say another 4 hours of sanding, which they insist has to be done only by them) then bottom paint it myself and splash the boat ... the yard where I am is too restrictive, and, at the same time, they are pretty much out of their depth on this type of repair project ... perhaps after a season of use, I can take the boat to Bellingham where there are boat yards that have dealt with plenty of Uniflites and their somewhat unique blistering issues. As this older vessel is new to me (and came to me for well-below market value, a factor I always have to keep in mind when it comes to the new money to be spent perspective), I have plenty of other projects / issues to assess, prioritize and plan for with this vessel ... and ... my budget is finite ... a proper repair job on the bottom is a rabbit hole I don't want to go down just now.

The way it stands, there is obviously moisture trapped in each blister, those blisters being visually evident (to be opened up by me) or not, and, a coat of bottom paint will still be moisture permeable I am told ... so, I don't see irrevocable harm occuring and it will be interesting to see what develops in the course of a season in the salt chuck ... a new environment for this previously fresh-water moored vessel.

FFF
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Old 04-20-2019, 12:02 PM
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2 ways of gong about this. Do it right, strip, fill, barrier coat, bottom paint. Around here a 42’ would be about 20-30k. Second option totally ignore the problem. Slap paint on what’s left of the good glass and use the boat. It will be the same problem 10 years from now. During that time do a search and find the very cheapest way to do it.
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Old 04-22-2019, 12:02 PM
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fireisland1 ... thanks for stepping up and helping me out ... I am inclined to adopt your second approach ... however, the situation (as I have communicated it to date) may have become somewhat clearer to me now. Whereas the Port u/w body exposed laminate within opened-up blisters was found to be hard, I have found that the underlying laminate within freshly opened-up (by me) blisters in the Stbd bow area is not as uniformly hard ... the putty knife I used to further scallop-open a section of sanded-open blisters encountered spots in the laminate (within the opened-up blisters) that yielded somewhat to the putty knife's angular corners if not absolutely careful in my technique ... so ... not the uniformly hard laminate condition I had hoped was prevalent in all areas.

Now I'm concerned about making a major mis-step by not doing something (other than just a coat of bottom paint) to protect the exposed laminate within the opened-up blisters ... I am left to wonder just how vulnerable the laminate will be over the short term ... i.e. over the course of a season moored (and used) in saltwater (as opposed to being moored in fresh water, as has been the case up until a month and a half ago).

FFF
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Old 04-22-2019, 02:22 PM
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Couldn't you fill the opened blisters with epoxy and then paint the bottom as a temporary solution until you decide on a permanent solution.
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Old 04-22-2019, 06:48 PM
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buzzk ... thanks for your input ... I've considered that but it seems like such a waste of time and materials if the epoxy cannot / will not bond ... due to the lack of full prep and drying out of each opened blister site ... I'm really trying to second guess if paint alone will be adequate to prevent significant, rapid damage to the exposed laminate ...

FFF
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Old 04-22-2019, 08:48 PM
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My Bertram had weeping blisters for years before I finally bit the bullet and dealt with it. The glass is so thick on the bottom of these old boats, I doubt that you’d do any significant damage by using the boat as-is for a season and dealing with the issue at a more convenient time.

As long as the boat yard didn’t go crazy and grind holes in your boat, it should be fine.

Pictures would help.
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Old 04-22-2019, 10:22 PM
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A couple of days to dry out the hull under the blisters is nowhere near sufficient time to achieve any reasonable drying. If you can’t wait at least 30 days (and in your case I certainly wouldn’t) then just put some surfacing epoxy filler over the opened blisters and paint the bottom. Use the boat for the summer, then put it on the hard in a more amenable yard and open all the blisters on the hull and let them dry out over a couple months time. Alternately peel the bottom and go from there, but there still needs to be a long drying period.

Or or you can just forget about the blisters and enjoy your inexpensive boat for a while.
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Old 04-23-2019, 07:51 AM
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twollman, Koocanusa Sam ... thanks for the advice ... I'll attach pics of the Stbd. Fwd. section of the hull ... one shot on 17APR19 before anything was done, then a 20APR19 overview shot (further Fwd. depiction) following my 'scalloping' investigatory probing, as well as several close-up detail shots of individual opened-up ('scalloped') blisters on that same Stbd. Fwd. section. FFF











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Old 04-28-2019, 12:39 PM
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Originally Posted by Koocanusa Sam View Post
... or you can just forget about the blisters and enjoy your inexpensive boat for a while.
... did just that ... put a coat of Sea Hawk AF33 over the mess and have deferred this issue for the season ... time will tell if it's substantially impacted and / or accelerated underlying laminate damage ... FFF
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Old 04-28-2019, 01:43 PM
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Originally Posted by Frankenstien View Post
... did just that ... put a coat of Sea Hawk AF33 over the mess and have deferred this issue for the season ... time will tell if it's substantially impacted and / or accelerated underlying laminate damage ... FFF
Looks familiar. I doubt itíll look any worse in a few months.

Lots of videos on how to fix blisters. Itís a messy, back breaking job. I started it and decided to pay someone 10 grand to finish it. I consider myself a hard core do it your-selfer , but I tapped out. Itís not a technical project per se, but laying on your back in a full suit and respirator grinding fiberglass gets old real quick.
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Old 04-28-2019, 02:12 PM
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You probably came across some of this, but Iíll say it anyhow.

Its not styrene in the blisters.

The blisters you can see now are just that, there are many thousands more lurking unseen just waiting to erupt.

The fix

You peel off all of the effected laminate and let it dry, which is only months if youíre lucky. And being in the NW ensures wet and humid weather, so you either do it indoors, or tent and use heat.

Then apply epoxy, and depending on the hull thickness you may need to add a layer or two of glass to rebuild the surface.

Now you start the fairing and painting process, which again is very labor intensive and costly. A year or so later you may be ready to put it back in the water.

Or, you basically do nothing but apply bottom paint. Doing it half way is a waste of any time and money expended. Even carving out the current blisters and filling them is a waste of time.
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Old 04-28-2019, 07:50 PM
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I have both dealt with boats with blistering--and studied blistering in the 80's as we were cruising Europe (Med and Baltic). The Uniflite problem is well known--and I have seen some hulls with blistering up the sides. Looking at your photos, your blisters seem superficial. If you ground those flush--and then took flexible battens along the bottom, you may see some of the deeper blisters--if they are there. I owned a Cal 46, which had some sort of a "blister job" in 1988 (the boat was 15 years old then) a couple of years before I bought it in Newport Beach, CA. There was a "Guarantee" from the yard--and the seller had the bottom painted. Unfortunately I was out of the country and did not see if there was blistering at that time--the bottom was smooth when I accepted the boat. (It was an as is where is purchase--and we basically completely rebuilt the boat). As I did blister repair, it was obvious that some of the blisters had been filled with a polyester based resin and thickening agent--not cloth. Also the boat had about 30 mils of epoxy on the entire bottom. I hauled in Port Angeles after 3 years in the PNW. There were a few blisters. I didn't really have the time to completely dry the hull, but did grind out the blisters, at about minimum 6:1 ratio around the edges. I washed with hot detergent and water, then acetone. I filled each blister area with concentric circles of 6oz fiberglass cloth and epoxy. Faired on the surface, with epoxy thickened with Cabosil. I next hauled the boat after sailing to Florida. At that time none of the original blisters had recurred--but there was a new crop. We had the boat out for several months as I had a complete LP paint job done--the blisters were opened and again dished out with an grinder and 36 grit paper. I also used an air powered die grinder with carbide bits to clean up the deepest part of the blisters--some over 1/4 " deep. Again, I prepped the bottom, and filled with concentric glass circles. We did not consider it worth a peel job.

I sold the boat in 1998 and the same person had cruised it full time/live aboard since. (21 more years!). The boat is still doing fine. Each time it is hauled a few blisters are dealt with--and back she goes...Probably at some point the entire bottom will have been epoxy/clothed over. But the blistering did not seem to be recurring where the original blisters that I repaired were. The boat is now 46 years old. I would have no hesitation taking the boat across the Atlantic or around the world, because of any hull/blistering issues. (The standing rigging should be replaced as well as other items.)

The thing not to do, is to put polyester resin or filler over the blisters--they often will come back in the same area.
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Old 04-29-2019, 11:12 AM
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Thanks for the additional input fellas ... I had to fight every instinct I had to try and do something immediately with the bottom as the situation described earlier in this thread evolved ... the conclusion I came to (and have more or less made my peace with, in no small part due to input received here at THT) is that the correct approach (for me, given the value of the vessel, the time and expense of a full-on proper repair job and the low probability of any kind of catastophic delamination occuring) is the one I eventually took ... nothing but superficial prep and then bottom paint ... in keeping with the final, alterrnative sentiments of Koocanusa Sam, ondarvr1 and others, both here and including PNW surveyors ... who have actually seen lots of these Uniflite boats / blisters ... in addition to this particular one.

I will say that I still firmly believe the watery chemical suspension inside the blisters is largely styrene-based (borne out by the proliferation on the hull bottom of mini-volcano-shaped white excretion solids [easily mistaken initially for small barnacles] at the center of blisters that have reached a certain size / internal pressure), and, is seemingly a by-product of post-'74 fire-retardent Hetron resin use breakdown. As I have read and come to understand, when the DuPont-supplied fire-retardent Hetron resin (formulated with liquid bromine) became no longer available sometime in mid-'74 and was replaced by the Hooker Chemical version (formulated with solid bromine), Uniflite's eventual fate as a boat-builder was sealed. For anyone inclined to take issue with my conclusions, have at it, however, know that I consider this an academic matter only at this point.

With respect to my new-to-me boat, I put her back in the water Friday the 26th ... and will move on to other issues which need addressing. Thanks again to all who stepped up with their experienced commentary and advice. FFF
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Old 04-29-2019, 11:21 AM
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The styrene crosslinks and becomes part of the resin structure, water does breakdown certain components in the resin, but it canít turn it back into styrene.

The liquid is water that has absorbed metal salts and canít move out through the laminate as easily as it came in.

I only replied because people read these threads and get some ideas that may not be accurate.
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Old 04-29-2019, 11:36 AM
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ondarvr1 ... fair enough ... and thanks for the continued input ... sounds like your grasp of the specific chemistry involved goes deeper than mine ... I do understand how outside water molecules can eventually penetrate permeable gelcoat due to their (smaller) size, whereas the chemical molecules in solution within a void are too large to get back through the gelcoat fast enough ... this results in internal pressure ... and a blister ... can we agree on that?

While I have always sought to better understand the Unilflite-specific blister issue and sorted through countless online descriptions of it (with my ultimate aim being taking the best course of corrective action[s], or, in my case, no action[s]), I must now re-direct my time and energy (vis-a-vis online reading) to other more pressing issues on this vessel. FFF
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Old 04-29-2019, 02:44 PM
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My background in resin and gel coat goes fairly deep, and Iíve been an expert witness in blister cases in court. I also advise companies on how to prevent blisters, and then how repair them correctly if they do crop up.

When blistering hulls first became a huge problem there were many companies popping up doing repairs. The early ďfixesĒ were short lived, with blisters returning far too soon. Once proven methods were developed the cost and hassle became too high for the average guy with a blistered hull to just jump in and have it done. It can still be difficult to convince people that unless itís done correctly, the chance of failure is very high.

I try to explain to people itís an all or nothing project, either do it correctly, or do nothing.

The intersting thing about brominated resins, is that although they donít burn well, the smoke is extremely toxic, so it is more harmful than just the black nasty smoke from normal resin.

Back then you just needed to have the laminate not support a flame, they werenít concerned about the smoke, but in typical fires you die from smoke inhalation, not from actually burning.
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