3m 5200 revisited...

[Shorefun]

So far I have tried the 5200, but had problems getting it into the holes. I had a lot of back pressure and it did not seem to be going well.

So next I tried injecting the Gorilla glue by putting it into empty caulking tubes and squeezing it in to the spaces. I found it is too easy to get too much in and it squishes out when you place weight on top.

Then I tried putting some Gorilla glue in the hole and then blowing it with air. I had mixed results. Some area bonded and another area did not. I am sure there is some technique I could refine by talking with Dave.

I still had another tube of 5200 so I thought I would try it one more time.
What I had noticed with the first try is my caulking gun did not hold the smaller tube very well. The tube pushed out at an angle and the ram was pushing against the side.
So duck tape to the rescue, I wrapped the tube in place. Then I cut the tip so it did not go much beyond the otherside of the plastic. You do not want the tip to bury in the foam and not come out.

I was drilling holes about 3" apart and found I could put some 5200 in and work it to a further hole. I would put a finger over the hole and push. Then you need to hold for a few seconds as the thick 5200 is slow to move. Then I would put duck tape over the hole I filled to keep the 5200 from coming out. Then as a last thing I put some metal bars and such directly over the holes so the weight pushed the on the holes and forced the 5200 to spread out.

The big draw back is the 5200 takes forever to cure. For me in NJ it is now a bit colder and the humidity is lower. The 5200 needs moisture to cure and likes to be a bit warmer then what the outside temp (well unheated un attached garage) is currently.

I am planning on doing more 5200. I am thinking I might first put in a very small amount of water and then blow it in with compressed air. This should help the cure.

So that is my current story. I am currently waiting for a more full cure on the 5200 to move on. Also I found HomeDepot is advertising the 5200 at $17.90 or so.

 

[Siamese]

Why are you drilling holes, and why are you putting 3m 5200 in them?

 

[Shorefun]

The plastic separates from the foam. In someplaces like where you feet go you can get a soft area.
So you drill small holes and get some glue in to stick them back together. The issue is the Luran S plastic is difficult to have good adhesion by a glue. The Gorilla glue does ok at sticking, especially where the moveement is limited. The 5200 does way better at sticking to the Luran S. Oh and you have to be careful with the glue as solvents can hurt the Luran S or the foam.

 

[justsomeguy]

The plastic separates from the foam. In someplaces like where you feet go you can get a soft area.
So you drill small holes and get some glue in to stick them back together. The issue is the Luran S plastic is difficult to have good adhesion by a glue. The Gorilla glue does ok at sticking, especially where the moveement is limited. The 5200 does way better at sticking to the Luran S. Oh and you have to be careful with the glue as solvents can hurt the Luran S or the foam.

He doesn't know you're dealing with a plastic Hunter hull.
I think...

 

[Benny17441]

Let me get out my crystal ball to see what the project is about.

 

[Crazy Dave Condon]

Send a private message with phone contact and I will tell you what I did. Then try it and report back as I now have arthritis setting in.
Folks do not use 5200 as it will not work over time and can lump underneath causing more problems

 

[Will Gilmore]

Gorilla glue also benefits from water as both a carrier into crevices the way flux works with solder and as a catalyst to encourage setting.

I don't suppose it really matters what your project is. But, knowing the details helps with visualizing your issue.

-Will (Dragonfly)

 

[Shorefun]

For those who are not aware, the Hunter 170 (140 and 210 I think) are a molded plastic shell. A plastic that is a relative to Lexan. With a layer of foam then fiberglass.

The plastic, I believe, shrinks over time among other things and has failures. Two failures are cracks and loss of adhesion to the foam. On my floors there was a large area that has a loss of adhesion which allows for some sponginess and such.

So there is the problem of getting the plastic to stick to the foam. You have to keep in mind that this plastic is very smooth and has troubles allowing glue to stick. So you need a glue that will get a decent stick to the plastic and thin enough to travel in an area with very little room. It all has to fit through a hole you drill into the plastic.

 

[JimInPB]

There are a few different flavors of 5200. The standard version takes about a week to cure at room temperature with middle of the road humidity. In dry or cold environments, it takes a lot longer. There is also a fast cure version that cures in a day at room temperature with average humidity. If the 5200 is not exposed to humidity, it does not cure for a very long time. If it is frozen, it does not seem to cure at all.

The Luran S, that the Hunter ACP hulls have for a skin, does not seem that similar to Lexan when I work with it. Lexan is stiffer & crazes more easily. Luran S is also used as bumper covers on cars & is also used in making some hot tubs.

I have found that West Systems epoxy sticks to Luran S very well. I have not subjected the hull to cold temperatures since the epoxy was applied, but it has been on there for many months & the repair is now the veteran of many tuna fishing expeditions.

 

[Shorefun]

I use lexan as a term others might understand better.
The simularity is in the surface on either is closed (molecualarly smooth) and will not allow good adhesion to most adhesives.

The Luran S is a different animal from Lexan in how it is more flexible, but tough. You can really tell the difference when cutting with the carbide bits. Lexan is much 'stiffer'. I am sure there are specific technical terms.

As for the differences in the adhesives. The Gorilla glue is hard when it cures and I find it wants to peel up once it starts on the Luran. The 5200 seems to have a higher stick to the Luran. It is also pliable.

My thoughts are the Gorilla glue works great until something happens to allow it to break free. Because it is a hard adhesive when cured it will not give to the movements of the plastic. Overtime I can not help but wonder if it can break free.

The 5200 is a rubber with give. So if a small area wants to pull away there is give and the other area will stay attached. So heating and movement (walking on it) allow for the flex and limited shear across the surface.

There are so many variables to the whole glue thing. Temp and humidity are big factors. So what I do here at sea level in NJ in 50 degree temps may be totally different then FL at 80 and 78% humidity.

Ya I know I am over thinking the whole thing. I was just out on the boat today. I pulled the weights and found the 5200 had set up on about 3' of foot area that did a week ago. The area was very level and solid. I was very happy with the results. The areas of Gorilla glue have a mixed bag. I might have messed it up some I am not sure. I will be talking with Dave soon and get his procedures and try his exact way with the Gorilla glue. I tried my variation of Dave's way and it went ok, but I was not thrilled with it.

 

[JimInPB]

I use lexan as a term others might understand better.
The simularity is in the surface on either is closed (molecualarly smooth) and will not allow good adhesion to most adhesives.

The Luran S is a different animal from Lexan in how it is more flexible, but tough. You can really tell the difference when cutting with the carbide bits. Lexan is much 'stiffer'. I am sure there are specific technical terms....

Flexural Modulus is the more technical tern, but I think that it is more productive for us to stay with layman's terms here, unless we have a reason not to. I am not sure that Lexan (a brand name of poly-carbonate) is the best choice of generic pronoun for Luran, but I like the fact that you are making an attempt to relate the conversation to something that many people are likely to be familiar with.

I am curious why you are using carbide bits to cut the Luran. I am also curious why you say that it is "molecualarly smooth". Do you just mean non-porous? Or are you trying to say something more?

...There are so many variables to the whole glue thing. Temp and humidity are big factors. So what I do here at sea level in NJ in 50 degree temps may be totally different then FL at 80 and 78% humidity.....

The lower temperature & humidity that you quote will cause a slower cure time, but the final results with 5200 should be the same. 3M advises against applying 5200 in temperatures below 40F. Tech sheets are readily available that provide a lot of helpful information on both the standard & fast cure versions of 5200 -
https://multimedia.3m.com/mws/media/576967O/3mtm-marine-adhesive-sealant-fast-cure-5200.pdf
https://multimedia.3m.com/mws/media/158782O/adhesive-sealant-5200-tech-data.pdf

 

[Shorefun]

So my perspective on materials taking coatings/ adhesives is shaped by my restoration of a 1931 Model A Ford Cabriolet. There is a lot of wrong information among restorers on how to put stuff on the body to make it level. After a discussion with a paint manufacturer I gained a different perspective on coatings and how the surface needs to be prepped before the next layer. So the question is what does the surface have to allow the next layer to attach. For example epoxy paint has microscopic holes open during the recoat window. This allows the paint to stick it molecules in and then the holes close up locking the molecules. Of course, most coatings will attach well to a properly "scratched" surface. The scratch can be mechanical like sand paper or chemical like an acid etch.

The surface of Lexan and Luran share a common trait in being 'very smooth' and not allowing a good bond by most adhesives. The surface is not very rough so there are not many spaces for something to bond.

Why did I use carbide bits, cause they cut well and do not clogg up. The Foredom tool and the carbide bit was easy cutting. I tested the Foredom tool vs the dremel on some Lexan. I also tested the holding power of Gorilla glue with the Lexan. Found it would peel off with a moderate level of effort. After using both Gorilla glue and the 5200 I found I could get a razer blade under the Gorilla glue mess I made and once I got it started it peeled up fairly easy and it left nothing behind. The 5200 was a bit harder to remove and left a little behind. Quite honestly they performed as I expected. Of course my real question is how they work years later. I guess I might find out though I might only own this boat a couple of years. Either sailing does not work out or I move up to something like a Catalina 22, only time will tell.

In any event, for the time being I seemed to have cause some people to come forward and offer some wisdom for which I am greatful.

 

[Crazy Dave Condon]

Spoke with Shorefun advising half inch hours every foot versus 3-4 inches using gorilla glue which he will inject in with squirt gun and then use an air hose to spread glue with and then weight floor down. He is mindful of the weather too. He will apprise when done