I purchased stock in ITW (maker of Plexus) ... Now What?

Sep 26, 2021
7
Hunter 170 Yale Lake, WA
Happy Sails to All ... new to the forum as of yesterday ... because I recently purchased a 1999 H170.
I am the former owner of a 2001 H212 that I bought used in 2006 and sold when I moved from California to Washington in 2010 ... not a single crack on that boat, just some very minor separation between the cockpit sole and the inner foam. Could be that my climate in California didn't lend itself to cracking. I loved that boat!
My recent purchase is a whole 'nother story. Every post that I saw asks for pics so I'll post some ... but it's basically the same old story ... motor mount is cracked and soft (read the thread detailing this repair and I'm not scared off yet), tabernacle is cracked but firm, and there are small cracks all over the cockpit and combings ... plus one LONG crack on the side that runs from the combing all the way through the deck/hull joint under the rubrail to the centerboard slot under the boat. Several cracks have been previously repaired (and reappeared) and a few have held, and several have had the 1/8" hole drilled that did not sucessfully terminate the cracking.
My first priority is to get the whole thing cleaned up and get it into my shop where it can dry out for a while ... the bilge drained for 10 minutes when I first got it LOL ... so I am sure it's soaked everywhere there is any place for water to intrude. My goal is to get it ready for spring sailing so I have 6 months or so to attack the repairs. I do have a shop to work in, but it's not heated and I do get freezing temps thru some of the Winter.
So ... I have skimmed through all the repair posts I can find here (and a couple other places) but am wondering if there is a consensus on how to approach the repairs. A few things:
* For delamination repair/injection on the cockpit sole ... I see reference to Gorilla Glue in several places ... there are a bunch of different versions of Gorilla Glue available ... is there a specific version that works best? I have also seen 5200 adhesive referenced with both positive and negative reviews ... any consensus.
* Plexus (or generic) is recommended for crack repair ... any limit to size of cracks before considering some fabric reinforcement? and am I reading correctly that fiberglass cloth can be saturated with Plexus and then laid up like using Polyesther Resin?
* Where to start and what to watch out for?
* Am I crazy?

Looking forward to getting this old boat back in sailing shape and to any insight from your experience will be much appreciated. Let me know if additional photos or info would help.

Thanks!
 

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Likes: Clark
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
For repairs, I would stick with epoxy.
With respect, dmax, epoxy is not the solution here. This boat's hull is plastic (Luran), and Plexus is design to aggressively bond with plastic. The OP is on the right track with Plexus.

These cracks look like the ones the previous owner of my 170 had to repair. Glad it was him and not me. Although some smaller cracks have appeared, the big repairs are holding.

To your questions:
* For delamination repair/injection on the cockpit sole ... I see reference to Gorilla Glue in several places ... there are a bunch of different versions of Gorilla Glue available ... is there a specific version that works best? I have also seen 5200 adhesive referenced with both positive and negative reviews ... any consensus.
THIS SOUNDS LIKE A GOOD SOLUTION, SINCE GG EXPANDS. I USED EXPANDING FOAM TO FIX MY DELAMINATION, AS THERE WAS A GOOD DEAL OF SPACE TO FILL. NO IDEA WHICH GG PRODUCT WOULD BE BEST EXCEPT TO SAY "THE KINDS THAT FOAMS UP".
* Plexus (or generic) is recommended for crack repair ... any limit to size of cracks before considering some fabric reinforcement? and am I reading correctly that fiberglass cloth can be saturated with Plexus and then laid up like using Polyesther Resin?
PLEXUS IS THE STUFF TO USE, BUT HAS A REALLY SHORT WORKING TIME (5 MINUTES OR LESS). YES, YOU CAN BED FIBERGLASS CLOTH OR MAT, BUT YOU WILL HAVE TO WORK IN SECTIONS.
* Where to start and what to watch out for?- START WITH SMALLER CRACKS TO GET A FEEL FOR THE PLEXUS. -WORK IN A WELL-VENTILATED AREA. SEROUSLY. PLEXUS EMITS REALLY NOXIOUS FUMES. OUTSIDE WOULD BE BEST, IMO. -BE CAREFUL FROM WHOM YOU TAKE ADVICE. PM CRAZY DAVE CONDON FOR TRULY EXPERT ADVICE. (HE WAS ON THE DESIGN TEAM FOR THIS BOAT).
* Am I crazy? YOU SAIL, RIGHT? SERIOUSLY, THE AMOUNT OF WORK YOU WILL PUT IN THIS HULL WILL LIKELY BE OUT OF PROPORTION TO ITS VALUE. IF YOU ENJOY WORKING ON STUFF LIKE THIS, THEN GO FOR IT. IF YOU DON'T, MAYBE LOOK AROUND FOR A 170 WITH A FIBERGLASS HULL.

Tips for the future:
-Keep the boat drained. Tip the trailer way up in the front to assure complete drainage. There's a lot of wood inside, and moisture is its enemy. I suspect it is the moisture combined with heat that is the cause of your damage.
-Keep the boat covered with a WHITE tarp. This is actually advice included in the manual. I found this 10' x 20' tarp to be ideal. I live in North Texas, and since aggressively attacking the cracks in my boat this Spring, I have not seen any recurrence.
-For the really tiny cracks, I have had some measure of success with super glue, just letting it seep into the crack and sanding once it has set up solid.
-Painting. Ah, painting. Not content with spot painting to obscure repairs, I used Krylon, and oversprayed with a clearcoat, but was not 100% happy with the results. I was finding that overspray was drying gritty, and trying to sand it smooth was taking me back to the original Luran. The clearcoat helped smooth things, but contrary to it's label claims, had a yellowing effect, especially under the seat mats, which I leave in place. If I had it to do over, I think I would either use a spray rig in an enclosed area to assure smooth coverage, or "roll and tip" with an appropriate paint. The important thing to remember is that Luran is plastic, so the paint you use should bond to plastic, or you should use a couple of primer coats. The simplest alternative is to just spray the repaired areas with Krylon and live with the slight mis-match.
-After chasing leaks for most of the first year of ownership, I found my most effective action was sealing the trunk at all possible leak points. I recall reading somewhere that this deck "floats" above the trunk. I used copious amounts of silicon sealer and it has decreased my water intake for an afternoon's sail to less than a quart from the four gallons I as getting before.
-For rudder hold-down and centerboard hold-up, I highly recommend the Sea-Dog Auto-Release Racing Mini Clam Cleat. Otherwise you will likely break or damage something every time you run aground.

Hope this helps, and best of luck!
 
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Sep 26, 2021
7
Hunter 170 Yale Lake, WA
Thanks for all the good advice ... especially regarding trying the Krazy Glue on the smaller ones ... I have a bunch of those too LOL.
I started routing out the cracks last night and determined that the battery powered Dremel that I have will not be sufficient ... only getting about 15 minutes out of the battery and takes 4-5 hours to charge ... another trip to Harbor Freight is in my future. Definitely planning to go the Plexus route ... and will leave the big side crack for last after I have some first hand experience ... may try sanding a 2" wide recess and laying in some fiberglass tape there.
Still looking for a specific recommendation on the Gorilla Glue (or something else) that I can shoot into the void under the cockpit sole to reconnect it to the core.
Also ... on a side note ... my trailer is a Vantage ... can't find the VIN on it anywhere ... anyone else have one and know where the VIN is located?
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
When I dealt with my lifting deck, I used expanding foam and the tubes that came with. I drilled 1/2" holes about 12-16" apart and worked fore and aft from each hole as much as I could. I tried white silicon sealant over the holes, but it attracted dirt. In order to address that and other deck imperfections, I applied self-adhesive foam deck material (see pics).

Can't help you on the VIN, sorry.
 

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Sep 5, 2018
214
Hunter 170 Northfield, NJ
So I have 2 seasons of getting out on my 170.

First off ONLY MA300 or equivalent adhesives. In a nut shell, the Luran plastic does not at the molecular level give most glues the ablity to hold even if you sand it. The MA type adhesives use solvents to 'dig' holes into the Luran so it can physically bond to the plastic.

Which brings be to the wonderful advice for Gorilla Glue. I can say it does not work. I did both the GG and 5200, in fact you likely found my posts in your search.

So back to my previous comment, no glue and adhere properly to the plastic. Basic materials science. When I heard about GG as a solution I questioned it effectivness over the long term. I have found the areas I put down with GG have pulled some. While the 5200 areas have not. While 5200 does not stick as well to the plastic like would to say fiberglass (it can peel apart fiberglass) because it is rubbery and has give along with a pretty good sticking power it does not give up it bond for the purpose of keeping the wide areas of the floor down to the foam.

I found running a small gas motor without neutral or reverse, that is one that you spin around to reverse, is a nightmare to control the boat. I am now at a yacht club and took the motor mount off. Plus the screws were not staying in the holes. I test all the screws with a quality philips head screwdriver and make sure they are able to be screwed down tight.

My point of view is your boat is too far gone to save. If the hull is cracked like that then it is too bad in my opinion. That being said. The only repair would be to use a lot of MA type glue. I would feather it back some, like an inch or two and lay up glass over the crack with MA glue.
You can buy different types of MA glue and you will want to talk to these people as they sell the stuff cheaper.

 
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Tater

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Oct 26, 2021
198
Hunter 170 Lake Logan Martin AL
While we are on this subject, I temp repaired my first crack today. It started just below the aft end of the starboard seat and went under the traction tape. It was about 1' long. Somewhere I read to stop-drill all cracks ASAP then come back later to finish. Where stop-drilling is concerned, bigger should be better to distribute the stress. I drilled a 3/8'' hole about 1/4" deep at each end. I then filled the holes with "Liquid Nails" for weather protection. The color match, if it doesn't change, is remarkable. It is truly a shame that this is the wrong adhesive. I'll add this to my winter project list.
 
Jun 8, 2004
10,024
-na -NA Anywhere USA
On the hunter 170 cockpit floor which has separated with voids noted. First there is marine ply underneath that sits on top of construction foam. The marine ply is coated with fiberglass on top. The plastic sheets are molded over the fiberglass.
I found thru trial and error the following will not work:
1. Epoxy will not adhere.
2. 5200 cannot be spread underneath plus too
Many holes to repai
3. Expanding foam will raise the deck more while
expanding during drying
4, screws that are screwed into the plastic will

here what I did and recommended

1. Remove the non skid from the cockpit floor
2. Where the voids were, I drilled 1/2 inch holes about a foot apart.
3. Filled holes with a lot of gorilla glue spreading it
via air hose
4. Laid good clean boards over the floor putting
weights on top of the floors Let dry for 24
Hours before removing everything.
5. Filled holes with Plexsus. Let dry. Continue
to fill when level. Sand smooth with wet and
Dry sandpaper. Then sand rest of floor for
adhesion of paint to the floor. Tape the entire
Edge of the floor. Cover the rest of boat.
Wipe off area to be painted with alcohol
6. Use white Krylon plastic paint only. I forgot
the specific color so I hope Simone will chime
In. If not get a color chart. Maybe
@Dave Groshong might know
7. Remove tape

it worked for me
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
Thanks for sharing with such detail. Fixing these pre-2005 170's can be frustrating, but when you have the right materials and some good guidance it's at least doable.
 
Sep 5, 2018
214
Hunter 170 Northfield, NJ
My experience is the gorilla glue does not stay stuck.

The 5200 will work to about 6" diameter area from a 1/4" hole. You pump some in and work the area up and down while holding your gloved finger over the hole.

This is based on what I did to my 170 several years ago. The area that I tried the gorilla glue is now loose by none of the 5200 area is loose. Fortunately I did not do much area as I did not believe the Gorilla would stick well over time.

Now for a full disclosure.
I live in NJ so the hull see wild temp swings. I used to use a grey cover which got the inside fairly warm in the winter during the day. I then switched to a blue tarp which still saw warm temps. This year I am not covering the boat and the surface is never hot to the touch. I checked with an IR temp gun and found in a 50 degree day the sun area is about 70. A far cry from previous years when the surface was MUCH warmer by touch.
My belief is that large temp differentials cause the plastic cracking problems. Every year I have been dealing with new cracks always on areas that the sun gets the hotest.
 
Jun 8, 2004
10,024
-na -NA Anywhere USA
The key with gorilla glue is a lot of it spread around with an air hose and pressed down evenly with weights on boards allowing it to dry for 24 hours. It worked and Hunter advised repairing the cockpit floor that way to others
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
My experience is the gorilla glue does not stay stuck.

The 5200 will work to about 6" diameter area from a 1/4" hole. You pump some in and work the area up and down while holding your gloved finger over the hole.

This is based on what I did to my 170 several years ago. The area that I tried the gorilla glue is now loose by none of the 5200 area is loose. Fortunately I did not do much area as I did not believe the Gorilla would stick well over time.

Now for a full disclosure.
I live in NJ so the hull see wild temp swings. I used to use a grey cover which got the inside fairly warm in the winter during the day. I then switched to a blue tarp which still saw warm temps. This year I am not covering the boat and the surface is never hot to the touch. I checked with an IR temp gun and found in a 50 degree day the sun area is about 70. A far cry from previous years when the surface was MUCH warmer by touch.
My belief is that large temp differentials cause the plastic cracking problems. Every year I have been dealing with new cracks always on areas that the sun gets the hotest.
Owners manual recommends using a white tarp. Mine survived the Texas summer well using that.
 
Sep 26, 2021
7
Hunter 170 Yale Lake, WA
Update: I have repaired several cracks with a Locktite brand MMA adhesive called "Plastic Bonder". Working in cooler temps in my shop (about 50 degrees) I have had about 10 minutes working time before noticing it begin to be tougher to work with. The first of the crack repairs were done about 3 months ago and none have reappeared. Even the wide crack on the side of the boat (I have only done the part on the combing so far) is holding ... its 1/4" wide and feathered back another 1/2" on each side ... eats up adhesive!!!
A couple things that I have noticed:
  • I have plenty of time to mix a full batch of material when working on larger cracks ... when doing smaller detail stuff I am running out of working time ... I am using 25ml cartridges
  • The material definitely pulls down into the center of the crack when drying ... not really shrinking because it does not separate from the sides ... just kind of compacts. This requires a second skim coat that has been tough for me to get even.
  • Once the adhesive/crack filler has dried it is way easier to sand than I expected ... 120 by hand/150 orbital/220 orbital ... just the nooks and crannies are a pain. Biggest thing here for me was getting past my fear of sanding thru the plastic!
  • The material dries to an ugly yellow/tan color
  • For painting ... I am getting good coverage and adhesion from
    • Rustoleum Plastic Primer (purchased from West Marine ... on sale it was reasonable)
    • Krylon ... Fusion All in One Gloss White ... which is a good color/gloss match (purchased at Fred Meyer ... sort of a regional version of WalMart)
Photos:
  • Unpainted crack that I put a second coat of MMA on after the first coat cured and contracted ... then sanded. It could be better but the sanding in the places not accessible with the orbital sander is a lot of extra work.
  • Painted crack ... not the same one ... this one did not get the second coat before painting ... recess is more visible but way less work
  • The bigger picture (pun intended) ... the crack on the left is the one in the second photo above ... the one on the right is the top of the BIG crack that runs all the way down and under the boat ... the bigger crack contracted a lot and I decided to try just sanding and painting without the second MMA application ... it's OK, second coat would have definitely been better and I'll try that on the next section
  • The same two cracks from an angle ... I may just say this is acceptable until I get the boat into the water for the first time and make sure there are no other issues and that the crack repairs hold up to actual use.

I'll also post some photos of the products that I am using (assuming that's allowed).

As far as finished results ... I am not very patient and therefore not very good at this LOL. I have decided that I am not inclined to try to make the boat look new, just to keep water out without creating an unsightly or rough surface. So I am going to forego the second application of adhesive going forward. The paint makes it look way better and for my intended use makes it acceptable.

The lifting in the cockpit sole and some other cracks in the cockpit area of the boat are going to be more of a challenge. Since the plastic layer is "loose" from the core there is no way to get an even V along the cracks ... the two sides displace and are not even ... it's going to need reinforcement to hold them in alignment.
I tried one area where I put down the MMA and laid some fiberglass cloth and tried to cover it immediately ... FAIL ... the MMA was too thick for me to get it to saturate the cloth without the cloth moving ... kind of like going 4 wheeling in a Geo Metro. But again, I'm not very patient. I am going to try again. I bought a 1/2" wide belt sander and will recess halfway into the plastic about 2" wide ... then apply MMA and lay cloth ... then after drying apply a second coat of MMA. I am going to live with the separation as long as it doesn't lead to further cracking.

The final existing issue that I'll have to deal with will be the motor mount. For now I am going to leave the mount removed and seal up the cracks and holes to keep water out. I know there's rotting wood in there so once I know that the rest of the repairs are going to work then I will go back and address that. It'll give me a reason to practice sailing out and into dock in the meantime.
 

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Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
Nice work!

I echo your observations. My practice is to overfill and sand back, but I get this little low spots too if I'm not careful. I suspect filling with Bondo would work since the MMA is doing the job of actually holding things together.

I actually used some to repair some cracks in my van's front bumpers and it worked great.
 
Sep 5, 2018
214
Hunter 170 Northfield, NJ
The crack on the side I would feather down the crack area. Then saturate some glass with the glue and lay it on for strength.
 
Sep 26, 2021
7
Hunter 170 Yale Lake, WA
Long overdue update ... but progress has been slow LOL. I finally got my boat in the water today. Since my last update I finished the paint, motor mount repair and some trailer related stuff. I still have some stuff to do but it's finally sailable. Today was a light 3 knot wind and 80 degree day for a shakedown cruise ... and everything passed. My rig definitely needs some tuning ... apparent even in the super light wind but I am just happy everything worked. I didn't get any photos today but here are a couple from last week when I was getting everything ready and back together on the boat after paint etc.
More soon ... especially about rig tuning and a new mainsail next spring (way better subjects to be worrying about than Plexus LOLOLOL!!!).
 

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