Parting out H170 in AZ

Apr 16, 2017
841
Federation NCC-1701 Riverside
Ahhh, got it. Like semi truck air bellows for suspension. Could look for 12 inch tire tubes for ATV's and stack them.

That means ill have maybe as many 14 innertubes in my hull never to be seen again.

The overhead suspension system works well enough. It pulls the deck right up and the holes are still plenty open even with the PVC pipe in the way under the deck. The PVC rod and the buntline knot tied aroubd it will be entombed in foam.
 
Sep 22, 2018
1,869
Hunter 216 Kingston
OH a lot of my “theories” are just goofy solutions looking for problems that have already been solved!! Just got thinking about the little airbag and my genius juices got flowing.

Your plan is well thought out and quite methodical so I’m sure it will be successful.

I’m somewhat amazed that they built the boat without some kind of stringer support for the cockpit floor, wouldn’t think it would have been that hard or costly to design in.
 
Sep 5, 2018
214
Hunter 170 Northfield, NJ
No epoxy will not properly 'bond' to the Luran. Sorry while it may seem hard to get off it is not structural.

I have played with trying to fix many plastic things over my life. I have always been a fix it kind of person.

The reason why you should not consider epoxy as a fix is because the plastic of Luran, plexiglass, lexan, plus a whole lot of others have a tight molecular surface with no good place for the strands of epoxy to lock into an create a bond. Even if you do proper sanding based on the instructions it still never really bonds to the plastic. I know I have tried. I have made many repair attempts to plastics only to have it come apart in use. Usually sooner then later.

The MA type adhesives are different. I am in heaven because now I know I can do structural repairs that will hold on plastics. They have 'solvents' that open up the plastic so the adhesive can get its strands co-mingled with the base plastic you are trying to repair. I was able to repair a RC controller gimbal that was broken that would not have otherwise been repairable.

For my boat I elected to not take the grinding of the cracks all the way through. Rather I made a channel to increase the surface area. This also puts the bond more in shear as opposed to going full through leaving 2 parallel edges. I also worked the glue in with a spreader. I am thinking the MA would push though a bit and come around to the other side.

To go a bit further..

In doing body work the best bond is epoxy direct to metal. While the epoxy is in the recoat window (not fully cured) its surface has microscopic holes that allow the molecule chains to slip into the holes. Then when the epoxy cures fully the holes tighten around the molecule chains. The epoxy needs to have the metal surface to the proper 'roughness' which depends on the mix. You need to read the tech sheet. Bondo type fillers need a certain range grit paper. If you use too course a grit paper then you create some deep scratch, but leave behind lots of flat surface between the scratch. You really want the most scratch per inch for best bonding (per a discussion with a tech person at a filler manufacturer). So working with the different materials means reading and understanding the properties. I go out of my way to ask these questions because I had a guy with 50 years experience tell me a lot of wrong things. I did what he said and things did not turn out so well in the end. I started asking questions to scientists and high level tech people to better understand how the different materials work and why.

Something to keep in mind.
The modern paints often use Isocyanates. They are really cool cause when you paint a car they link up into one big molecule covering the car. BUT, they are very dangerous to your body. Most solvents they just try to kill your nervous system or various organs (how much do you like your liver and kidneys?). The Isos cause an allergic reaction. Hours later you might feel a tightness in the chest the first time. Each time it gets worse as you get industrial Asthma. Some people get it fast and strong and by their 3 exposure they almost die. Once you are allergic you are done being around it.
So here is the interesting part. Most guys spraying the stuff are fully covered. It is when they are mixing and it get absorbed through the skin as the number one exposure point.
So stay safe and know what can kill you in the stuff you are using and take precautions.

My personal advice which honestly does not have a lot of experience....
Do not screw around. If you need to do glue the Luran to itself get the MA300. Bonding over a large area like the foam to the Luran 5200 will stick well enough. The Gorilla glue is probably ok for very tight bonds, but if there is any gap and it foams you can figure on no bond between the foam and the plastic.
 
  • Like
Likes: BobbyFunn
Apr 16, 2017
841
Federation NCC-1701 Riverside
I found a left over west system activity kit (101-6) in the paint job box and there is one packet left. Ill test that "neat" against the pl 3x.

Next weekend Ill have to remove the cores from the luran.
Loctite PL 3X wins.

First test involved grabbing one core in each hand and alternating pulling them apart. Some cracks were heard.

Next test involved grabing the luran and then placing my thumbs down on each core so the luran bends away from the core. Epoxy cracks immediatly, and after working it a little there was just a little bit of epoxy holding down the core. The epoxy did a great job of sticking to the core but only a couple remnants if epoxy are on the luran.

I spent a few more minutes doing the same to the PL3X and its not coming off without breaking the panel or the foam.
 
Sep 22, 2018
1,869
Hunter 216 Kingston
Loctite PL 3X wins.

First test involved grabbing one core in each hand and alternating pulling them apart. Some cracks were heard.

Next test involved grabing the luran and then placing my thumbs down on each core so the luran bends away from the core. Epoxy cracks immediatly, and after working it a little there was just a little bit of epoxy holding down the core. The epoxy did a great job of sticking to the core but only a couple remnants if epoxy are on the luran.

I spent a few more minutes doing the same to the PL3X and its not coming off without breaking the panel or the foam.
Can I ask for clarification on the foam used in your test?

It looks like you used two of the “cores” you removed from the cockpit floor without the Luran layer, turned upside down so FRP is on top and stuck them with epoxy and the Loctite product to the big piece of Luran you had removed. In other words the foam is the stuff Hunter used during construction. If that is the case it proves that neither the epoxy or the Loctite “eat” the original foam.
If you made up new cores with the foam you just bought for the project it also proves the two products you tested don’t “eat” the new foam.
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
Can I ask for clarification on the foam used in your test?

It looks like you used two of the “cores” you removed from the cockpit floor without the Luran layer, turned upside down so FRP is on top and stuck them with epoxy and the Loctite product to the big piece of Luran you had removed. In other words the foam is the stuff Hunter used during construction. If that is the case it proves that neither the epoxy or the Loctite “eat” the original foam.
If you made up new cores with the foam you just bought for the project it also proves the two products you tested don’t “eat” the new foam.
Yep. The makers of urethane foam mixture advertise it is safe for poly resins and expoxy. Styrene foams (blue and pink foundation insulation) would be risky, but not urethane foam. PL3X, Gorilla glue, 5200 i expect are all the same since they are all moisture curing urethane products as well. i did dab water on the luran before appling the PL3X (but did NOT wipe it clean at all)

I did resuse the drilled out cores for the test. Now i need to rescue my luran from a foam limpet. Its still stuck.

If i had tried to be clever and inject expoxy between the deck and the foam, it would have delaminated again by the time I put the mast back on.

If using epoxy..it has to be thick, on a well prepared surface that is built up enough that doesnt flex. Its game over for bendy thin epoxy.
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
Battery Mount:

Not sure if i got a factory install or not. Im guessing no.

The battery is about 50lbs and these mounting straps are simply 4 screw ran through the luran.

Shouldnt this have a backing plate and have an epoxy plug that seals the core? Ill never see the backing plates once that core is filled back in.

I really dont want to put this back on...

Are there better ideas? Is there a good way to anchor into the foam without going all tje way through. Make a hollow cone and fill it with epoxy, or get a gas motor?
20190529_192140.jpg
 
Sep 5, 2018
214
Hunter 170 Northfield, NJ
Well you could get one of those lithium battery motors but they are super $$$$$.
I have a 2.5 Yamaha (Tohatsu) I got used for $125 that needed a good carb cleaning. It has the 18" shaft (I got lucky it was long enough).

My thoughts, either you brace the crap out of it in case or just keep it simple and don't turtle.
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
Thats a great price for a motor. Id be skittish buying a used one for fear of it being stolen from the guys on the cruising forums. :)
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
Those are cool. I want one in the car trunk and another in the hurricane box.

How would you use this for the deck? From underneath?
I was thinking that it might be possible to put them under the foam layer & push it up to meet the outer skin when you are trying to glue them back together. The later suggestion of using an inner tube also seems to have merit.

I don't know how much give the foam has. If it is brittle, then pushing it up may be a bad idea.
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
The urethane "stringer" columns have been figured out. There were some challenges so I'll bring them up. The hull and the deck are not level so it was brutal trying to measure, cut, install, remove, measure cut, install. In addition its hard to measure when the deck will be higher when clamped. There didnt seem to be away to place the poster board mold in place and get a good fit for the top and bottom.

What works really well is to make a top section of about 3 inches, then make a second tube that fits perfectly inside the top section, that reaches all the way to the bottom, and up almost to the FRP.

The next step is to make a mark on the fingers 2 inches from the tips. Then, place a couple tabs of duct tape on the top of the top section, roll it up, place in the hole, and unroll the form.

Push the form in under the deck untill the mark on the fingers are lined up, then push the tape up under the deck.

Finally, roll up the bottom form, place in the hole, unroll and slide it to the bottom. The bottom might need to be adjusted for the hull angle and replaced. The top section is taped flush to the deck underside, and the bottom of the mold is resting tight against the hull and supported by the top piece.

Oh, wear gloves...my hands are pricked all over with the FRP.

Specs:
Deck cores are 4 inches in diameter.
Foam mold is 8 inches in diameter.
Each core mold will support 37 square inches of decking, plus the entire puck, and also form a foam mortise into the deck core section drilled out.
 

Attachments

Last edited:
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
No epoxy will not properly 'bond' to the Luran. Sorry while it may seem hard to get off it is not structural.

I have played with trying to fix many plastic things over my life. I have always been a fix it kind of person.

The reason why you should not consider epoxy as a fix is because the plastic of Luran, plexiglass, lexan, plus a whole lot of others have a tight molecular surface with no good place for the strands of epoxy to lock into an create a bond. Even if you do proper sanding based on the instructions it still never really bonds to the plastic. I know I have tried. I have made many repair attempts to plastics only to have it come apart in use. Usually sooner then later.....
Thank you for the heads up. This is good information.

Since I seem to have had good luck so far, I would like to consider the possibility that the West 105/205 "epoxy" mix, may be somehow different from the other epoxies that you have worked with in the past. I am curious what epoxies you have tested? I am also curious why you seem to lump lexan & plexi in with Luran. I know that they are all plastics, but I am not aware of them being in the same family. I'm not saying that you are wrong. I am saying that I don't know & I would like to learn more about this.

Thanks,
Jim
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
I don't know how much give the foam has. If it is brittle, then pushing it up may be a bad idea.
No doubt! Youve had a core in your hand...brittle indeed. Im just trying to pull the deck up to the original level. Im thinking i will also need to put some weight down on the deck. The picture early on that shows the hollow space under the deck, indicates that the deck core may aready have cracked over on the right at the end of the centerboard trunk. The starboard side is nowhere near as low as the port side. Id like to release the suspension clamps some before pouring the foam columns so that the suspension force is not left transferring to the lower hull afterwards.
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
@JimInPB did you use any fillers for your repairs.

MMA is the best product for repair of luran, and I know from experince that expoxy is a terrible glue, but epoxy with fillers is solid for building up mass.

As soon as this deck is fixed im moving on to the motor mount to emulate your repair. You still happy right?
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
Battery Mount:

Not sure if i got a factory install or not. Im guessing no.

The battery is about 50lbs and these mounting straps are simply 4 screw ran through the luran.

Shouldnt this have a backing plate and have an epoxy plug that seals the core? Ill never see the backing plates once that core is filled back in.

I really dont want to put this back on...

Are there better ideas? Is there a good way to anchor into the foam without going all tje way through. Make a hollow cone and fill it with epoxy, or get a gas motor?View attachment 165430
My 170 has a group 27 battery (for a trolling motor) that is in a box that is just held down by the 4 screws it came with. So far, so good, but yes, backing plates would be preferable.
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
@JimInPB did you use any fillers for your repairs.

MMA is the best product for repair of luran, and I know from experince that expoxy is a terrible glue, but epoxy with fillers is solid for building up mass.

As soon as this deck is fixed im moving on to the motor mount to emulate your repair. You still happy right?
My motor mount repairs were well documented in a 2-part write up -
https://hunter.sailboatowners.com/mods.php?task=article&mid=11&aid=100114&mn=170
https://hunter.sailboatowners.com/mods.php?task=article&mid=11&aid=100115&mn=170

I used only Foam, fiberglass cloth & epoxy, with no fillers, in that repair. (& a little 5200 on top, to glue the original skin back in place) Yes, I am still happy with the repair. It was a major improvement.

In other repairs that required a small area to be filled, I cut up scraps of glass cloth into thin strips, tore them apart, & used the loose fibers as filler. That has worked well for me on a few small projects.
 
Sep 22, 2018
1,869
Hunter 216 Kingston
On the other hand...Near the mainsheet swivel, it is 1foot from the skin to the hull. Might be ideal for placing a recessed battery case there...then use that big hole for using adding and removing expansion devices. Then sink the recessed battery box to seal the hole.
Did you abandon this idea?