Epoxy or Polyester - Which for a renovation

[DPManley]

Well, I read so many great threads in the forum that I thought I was going to just post after I finished.
Right off the bat, I have a question.
First the situation:
1967 Larson (I don't know Model) about 17' Square glass, outboard.
1978 Evinrude 85 HP - Engine runs strong. I replace impeller last summer and figure I can go two years before replacing again.

The floor had some soft spots, and was rotted through in two spots. We planned to use it till it died and walk away. We ski 10 to 20 times per summer and I just can't buy the ski boat I want for about two more years so I decided to repair the floor and nurse it through two more summers. I expected bad stringers and worse and I don't have time or money for that.
I carefully cut out the bad spots and found that the stringers had been replaced with foam at some point. I heard that the transom was replaced in the late 80's so it looks like it was a more thorough repair. So far, so good!
So I have replaced the rotted frame under the floor, on top of the foam. I am using whats left of the old floor as a template to cut new plywood. I plan to resin coat the ply, add a layer of mat, install and cover with a second layer of mat, joining the floor with the hull.
So here is my question: Can I use polyester? For my application, all instructions I have read seem to indicate that Polyester is good enough for this, except that I need to lay the new glass on the hull around the edges. It seems like the poly is not right for joining with the old glass.
Will poly work or must I spend twice as much for epoxy?





This was about 3 years ago

I tried to post the picture of the new frame in place but I am having upload problem.

 

[DPManley]

Re: Epoxy or Polyester - Which for a renovation

OK - After posting, the "similar threads" showed me several links. And a very even score for using either epoxy or poly.
Some further notes:
I don't want to spend if I don't have to. The purpose of the repair is to replace the floor and seal it well for two years and the next owner.
I will prep well - grind off junk and vac, blow, wipe down the areas where the floor will join to the hull.
Bottom line: I will spend if the bond will fail with poly. I don't want to do junk work, but I am not doing a 30 year restore.

My latest pictures are too big to upload. I will figure it out to show the whole project.

 

[Bob_VT]

Re: Epoxy or Polyester - Which for a renovation

Poly resin is fine. Your boat was originally poly built.

Two primary differences between poly and epoxy .......... poly shorter working time and good strength ve epoxy - LONG working time and over twice the strength. Poly cheaper so you get what you pay for.

If you have any intention of using gel coat then use poly.

The cheapest......ploy + exterior plywood + enamel (rustoleum or tractor supply paint). The fiberlay resins will work fine Marine Repair Resins

We have all of it here Fiberglass & Epoxy Boat Repair & Building PLUS there is an additional discount in place right now

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[JASinIL2006]

Re: Epoxy or Polyester - Which for a renovation

If you're only going to own it for a couple more years, I think it would be hard to justify the expense of epoxy. Many, many of us have used polyester in our restorations, so I think you'll find there is lots of expertise here, should you need help as you get into the project.

 

[Woodonglass]

Re: Epoxy or Polyester - Which for a renovation

Here's something you need to be aware of. I KNOW you only want to replace the floor/deck but this statement is of some concern..."the stringers had been replaced with foam at some point. I heard that the transom was replaced in the late 80's so it looks like it was a more thorough repair. So far, so good!" A few questions... 1.) Are you saying the Hull has been totally filled with foam all the way to the bottom of the floor/deck? 2.) Have you core sampled the Foam, all the way to the bottom of the hull to ensure there's no water entrapped in it? 3.) Have you "Flex Tested" or Core Sampled the Transom to ensure it is still sound? It's been 25 yrs. since the previous repairs and that's more than enough time for problems to re-occur. I'd highly recommend you do a thorough inspection of all the structural components before re-installing a deck and covering up potentially unsafe/hazardous issues.

Like I always say, It's your boat and you are free to do as you see fit, but again, I would recommend a thorough inspection of all the components to make certain they are sound.

 

[DPManley]

Re: Epoxy or Polyester - Which for a renovation

Good advice as always, thanks. So far, I plan to use poly.

I really want to post a picture of the bottom with the floor removed but my files seem to be too big. I guess I need to use the Photobucket method? The stickey has good instructions but I get an error with any picture from my newer camera. They are over 4mb each.

For Woodonglass -
There is a clear channel down the middle from the dashboard back to the transom drain, approx 12" wide, bare fiberglass hull. On each side is a "wall" of roving cloth glass and then a foam filled channel. Each channel is 10 or 12" wide and seems firm. A little of the bow is also foam filled under the deck. The foam does not seem wet and I don't see any signs of water under it. Rain did get in this week so now I have to dry everything before any glass - I figure i will seal it in about 4 weeks. I still need to cut the decking to shape so plenty to do.
Transom has no cracks and I have had no flexing that I know of. I get no flex when the motor is raised, but I did not officially "test" and I did not drill core samples. I always use a transom saver, but just on and off the ramp and in my driveway, I do not notice any flexing.

I must say that if the transom is bad, I would probably abandon the project.

My thought is that phase two of a real restoration of this boat would be remove the "top half" - split the hull at the rub rail - replace transom and repair the upper body and gelcoat. I don't want to do this but I do want to make the floor replacement a proper fist step. I hope that this will be a good fishing or family boat for many years while I get a dedicated ski boat.

 

[DPManley]

Re: Epoxy or Polyester - Which for a renovation

OK - Some decision made, life is not always easy.
This year, replace floor and repair hull. That gets me back on the water for summer, and my first experience with fiberglass. In the fall, I will decide if I am up to removing the cap and doing the transom, along with restore of upper deck (I will need to learn gelcoat). The transom has some rot in one corner and stains on the outside make me think it should really go. I can't do it this season although I realize I am partway there with the floor work so some wasted effort.
I have always wanted to do a real restore on this boat - it is a nice family boat. After reading several restore threads (Woodonglass' Flamingo.....) I cannot abandon her.
So - Poly resin following the instructions on this site for floor replacement this year. I have also stared a thread for the hull repair as that scares me a little.
Around October, after I drag my wife around the lake a few times, I will tear off the top and start phase two. I hope.

 

[DPManley]

Re: Epoxy or Polyester - Which for a renovation

I see that the picture I was fooling with also attached. I had started to copy the stringer configuration that was under the rotten floor. Now that I have read more, I will need to rip out more and fix what the PO did. That wet foam is a problem. One of many.

 

[Woodonglass]

Re: Epoxy or Polyester - Which for a renovation

It never ceases to amaze me what some people do to just put a new deck on a boat. WOW!!! Yeah IMHO ALL that will have to come out, the stringer channels cut out and ground down to the hull and then new stringers and bulkheads fabricated and tabbed in with fresh resin and glass. If you de-capitate her, (which you will need to do) then I'd build a cradle and flip her so you could repair the keel and the bottom of the hull more easily. Grind it down a bit with 24 or 36 grit sanding discs and a 4 1/2" grinder and then apply a layer of CSM and then 2 layers of 1708 and a final layer of CSM. For the scratches and gouges dremel em out or use a grind stone on a drill and then clean with acetone and fill withe Resin thickened with Glass bubbles and a bit of Cabosil. Get yourself a Preval Sprayer if you don't have a spray gun to do your spot touch ups with gelcoat. As always, it's your boat and you're free to do with it as you see fit.

 

[73Chrysler105]

Re: Epoxy or Polyester - Which for a renovation

OK - Some decision made, life is not always easy.
This year, replace floor and repair hull. That gets me back on the water for summer, and my first experience with fiberglass. In the fall, I will decide if I am up to removing the cap and doing the transom, along with restore of upper deck (I will need to learn gelcoat). The transom has some rot in one corner and stains on the outside make me think it should really go. I can't do it this season although I realize I am partway there with the floor work so some wasted effort.
I have always wanted to do a real restore on this boat - it is a nice family boat. After reading several restore threads (Woodonglass' Flamingo.....) I cannot abandon her.
So - Poly resin following the instructions on this site for floor replacement this year. I have also stared a thread for the hull repair as that scares me a little.
Around October, after I drag my wife around the lake a few times, I will tear off the top and start phase two. I hope.

I know you wnt to get out and enjoy her but if the transom is bad you may be lucky and get to enjoy her for a little while but when that bad transom lets go the boat will more than likely sink when the motor rips it off the back of the boat. And you sink the boat with your wife in it then there is no way the admiral is going to let you get another one or get in one with you again.

 

[jbcurt00]

Re: Epoxy or Polyester - Which for a renovation

This WAS bought as a water ready boat, AND passed what they thought was a thorough inspection:

The safety of you & everyone aboard is more important then ANYTHING else. I'd have a problem KNOWING that there is rot lurking in my boat, and taking anyone out on my boat. Even if I 'thought' it'd be safe for a trip or 2.

Stuff happens, perhaps not of your doing, regularly on the water. When it does, you want to KNOW that you, yours & your boat are capable of dealing w/ it.

 

[DPManley]

Re: Epoxy or Polyester - Which for a renovation

That picture is worth a thousand words!
I am grinding and fabricating as time allows. With a little luck, we will be on the water sometime this summer.
Thanks to all for the advice.

DM

 

[Woodonglass]

Re: Epoxy or Polyester - Which for a renovation

Post up some pics of your progress!!!

Don't forget to "PIN" your location on the New iBoaters map in the STICKY section at the top of the Forum. iBoaters Where Are You??

 

[DPManley]

Re: Epoxy or Polyester - Which for a renovation

I updated my location and put a pin in the map.

Forum Etiquette question:
Should I start a new thread for my restoration or just keep going here? I do have some progress and new questions.
I do not believe that I will take on a new career grinding fiberglass.......

 

[jbcurt00]

Re: Epoxy or Polyester - Which for a renovation

go w a new thread

 

[jigngrub]

Re: Epoxy or Polyester - Which for a renovation

You'll be fine to keep going with this thread and all of your information will be in one place.

Since you're a first timer it would be better to post timely updates with what you intend to do next so we can help you stay on the right track. I've seen a few threads lately that took different routes than they should have but you can really say anything to help these people because the work has already been done and it makes me a little disappointed when I see this and know a better job/method could've been done.

 

[Woodonglass]

Re: Epoxy or Polyester - Which for a renovation

Just edit your first post in this thread and click the Go Advanced button. You can then Change the Title of the Thread to better reflect what you want your Project to be called.

 

[DPManley]

Re: Epoxy or Polyester - Which for a renovation

OK Thanks guys. I may change the title but moving on here for now.

So I removed the floor and found a support frame that sits on top of foam filled stringers. I had planned to simply replace the frame and floor. I posted this picture:

That's when the forum re-directed me. Since then, I removed the frame and started removing some of the foam. I have also done some grinding on the sides and in the bow.

I left a little foam in front that was dry. The "srtingers" are roving with foam filler, no top. The frame sat on top of the foam with screws though the roving. This is the thickness of the sides of the stringer:

So - I will be removing the stringers and replacing with plywood. The stringers and floor will be sealed per the process recommended here in the forum - Poly seal, CSM/cloth/1708, PB filling gaps. Foam poured in through holes and plugged prior to final layers of glass.
I also examined the transom. There is no flex and drill holes and inspection shows rot at the bottom near some exposed holes but solid through the center and to the edges. I will be replacing the transom at the end of this summer. To do that I will un-cap her and re-finish the upper sections also.
The renovation has two goals - make a great boat so I can sell it for a fair price. It's not a classic car so I won't make money, but I want to do a good job so I get as much as possible. The second goal is to learn the skills so I can do even better on the next boat.

Questions:
Is it better to have stringers be one piece and fit bulkheads between them or make bulkheads one piece across and fit the stringers between them?
Am I grinding enough? I cut through all glue and old glass that was used to hold in the old interior. In the picture above, you can see un-ground areas on the far right with carpet glue and some thin glass cloth stuck to the hull. Lots of old PB in some spots. On the left is an area that is ground. A pattern comes through that looks like roving. It is hard and appears solid.
I plan to finish the interior with white gelcoat, so I am grinding well up under the gunwales.

 

[DPManley]

Re: Epoxy or Polyester - Which for a renovation

I was able to re-size some pictures.
This was before I removed the floor.


When I took up the floor, I found this.

As Mentioned, I started replacing the frame, then read the threads on proper replacement.

DM

 

[DPManley]

Re: Epoxy or Polyester - Which for a renovation

So I am reading Pink-Panthered thread on his restore, and I see this picture:

Is it possible that I should not cut the fiberglass stringers from my Larson but simply re-foam them? That would save me a lot of glassing below the floor.