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1970 E32 Annapolis MD area

M

Macgyro

Amazingly Still Afloat
Blogs Author
Cockpit area soft spot- 6"x6" Area of Delmanition and cracked

e32stx said:
Oh yeah... and don't forget the other rotted bulkhead. May as well knock em all out at the same time.

How bad is the damage at the rudder post?
I nearly put my foot through the cockpit at the tiller handle head.
Click to expand...


The surveyor mentioned that, and I noticed that when I looked at it. It needs new coring and to be re-fiberglassed again. I think that will be the first exterior repair I do. I think "Tenders" has a good post about replacing the entire cockpit floor, I may just do the area that's buggered up though at first. I'm not entirely sure if it affects the tiller head, but when I re-core it, I'll beef it up as necessary.

BTW, the fuel tank leaked as soon as I put gas in it. Replaced it before the survey with a 12 gal plastic Moeller. I don't plan on any trips down the ICW, so a smaller fuel tank is fine with me.

-Dean
 
M

Macgyro

Amazingly Still Afloat
Blogs Author
Polyester Resin?

Okay,

I just got back from Home Depot, and found Bondo Polyester Resin for $36 including hardener. This would obviously be cheaper than West System Epoxy, but I'd like to hear you's guy's opinions on strength, and quality of polyester resin over Epoxy, and if anyone has experience with polyester resin at temperatures around 40-50 degrees F. I know I can use the West System Fast Hardener down to 40 degrees, and I have to move the boat from its slip in March, so I will most likely be on the borderline temp-wise.

20131213_112923.jpg20131213_113003.jpg
Dean
 
tenders

tenders

Innocent Bystander
Polyester is OK for building standalone structures (it is after all what our boats are made of to begin with) but it does not have the adhesive ability or strength to use in any structural boat repairs whatsoever, whether that's to wood or existing polyester.

Epoxy is the only way to go. We can certainly debate whether the premium charged for West System is worth it (there are other manufacturers, including System Three and Raka, probably others) but the only use to which you should put polyester after the boat pops out of the mold is gelcoat repair. I've found the value-add material West has published over the years (epoxy repair techniques, EpoxyWorks magazine, etc) to be so useful that I'm happy to pay the premium and have never had a problem with any of their products.

Also, you have to be careful when buying fiberglass cloth. Most of it you'll find in hardware stores is designed for bodywork, and contains an finishing chemical that works with polyester but is not compatible with epoxy.

My sole supplier for West System resin and fiberglass is Defender.com.
 
P

PDX

Member III
Polyester resin can certainly be used down to the temperatures mentioned. I would not use it for this repair--epoxy makes a much better wood adhesive.

If you're going to use a bevel joint, I'm not aware of a tool that will allow you to do this, in place, with the appropriate amount of bevel. There is a rule for scarfs, being a certain multiplier of the thickness of the wood. I don't remember it but I would bet it needs to be at least four inches if you're talking about a 3/4" bulkhead. The only way you're going to be able to do this, with the section of bulkhead in place, is with a grinder. It won't be perfect, but it doesn't need to be necessarily. I assume you're going to wrap both sides with cloth and resin. Epoxy does not require a tight joint fit when gluing, just make sure you give both sides a generous wetting out and then use thickener for the actual glue up.

Have you used epoxy before?
 
M

Macgyro

Amazingly Still Afloat
Blogs Author
Polyester vs Epoxy

That's kinda where I was headed, but it's nice to hear confirmation. I have used epoxy before, but not on this scale, and not vertical. I've been reading up on West System's guides and some old wooden boat magazines. I've already got the pumps for west system, so I'll stick with that, but the 1708? fiberglass cloth looks like it's made by MAS. I'll see about ordering that from defender marine, unless I can find a local supplier. I've got a boat restoration acquaintance I'm going to order the marine ply from and hopefully pick his brain as much as possible before he starts charging me. I figure I've got about 75 days to become an expert before I start gluing up the new section of bulkhead.

Maybe I'm a little confused about the beveling vs. scarfing definitions. My understanding was that scarfing (let's use the 4" example) would cause an overlap of approximately 4" and a bevel was like a butt joint except that it was only for the center 3/8" of the 3/4" plywood, and each section of the plywood was sanded out at an constant angle to 6-8" on the forward and aft faces of the plywood to give the laminated layers of fiberglass and epoxy room to build up resulting in a nearly flush repair. From what I've read about epoxy, would a slightly thickened (high density filler) epoxy be pushed into the joint (from the head area) between the two pieces of ply forming the bulkhead, and soon thereafter laminate the fiberglass/epoxy to the correct thickness? Then repeat on the aft side?

I'm also thinking that if I can position the new bulkhead section properly, would a 4" scarf joint utilizing an unthickened epoxy on the joining surfaces, then maybe a wider layer of fiberglass (around 30") be just as strong?

Still reading up on it. Thanks for the feedback, I really am formulating a plan and modifying it based on your advice in addition to what I can gather from other sources.

-Dean
 
P

PDX

Member III
Macgyro said:
That's kinda where I was headed, but it's nice to hear confirmation. I have used epoxy before, but not on this scale, and not vertical. I've been reading up on West System's guides and some old wooden boat magazines. I've already got the pumps for west system, so I'll stick with that, but the 1708? fiberglass cloth looks like it's made by MAS. I'll see about ordering that from defender marine, unless I can find a local supplier. I've got a boat restoration acquaintance I'm going to order the marine ply from and hopefully pick his brain as much as possible before he starts charging me. I figure I've got about 75 days to become an expert before I start gluing up the new section of bulkhead.

Maybe I'm a little confused about the beveling vs. scarfing definitions. My understanding was that scarfing (let's use the 4" example) would cause an overlap of approximately 4" and a bevel was like a butt joint except that it was only for the center 3/8" of the 3/4" plywood, and each section of the plywood was sanded out at an constant angle to 6-8" on the forward and aft faces of the plywood to give the laminated layers of fiberglass and epoxy room to build up resulting in a nearly flush repair. From what I've read about epoxy, would a slightly thickened (high density filler) epoxy be pushed into the joint (from the head area) between the two pieces of ply forming the bulkhead, and soon thereafter laminate the fiberglass/epoxy to the correct thickness? Then repeat on the aft side?

I'm also thinking that if I can position the new bulkhead section properly, would a 4" scarf joint utilizing an unthickened epoxy on the joining surfaces, then maybe a wider layer of fiberglass (around 30") be just as strong?

Still reading up on it. Thanks for the feedback, I really am formulating a plan and modifying it based on your advice in addition to what I can gather from other sources.

-Dean
Click to expand...

1708 cloth consists of two layers of 17 oz biax with a mat backer. 1700 cloth is the biax alone. I would stick with 1700. The mat adds unnecessary weight and bulk. Also, mat is incompatible with epoxy unless specially made to be epoxy compatible. Polyester dissolves the adhesive that holds the mat strands together (this is the intended result). Epoxy does not.

The scarf joint is stronger than the butt joint you describe. Essentially with your butt joint you're trading a 3/4" sheet of plywood for a 3/8 and then wrapping it with glass. If the only area you're replacing is that rotted out hole down at the bottom, either joint will probably do. But I don't understand your concern with getting a flush surface. This is not an appearance grade repair anyway, is it? Isn't it back behind the settee? My preference would be a 3/4" sheet of plywood (glued back together with a scarf joint) wrapped with glass.

Any wood joint you use, whether butt, scarf (which is a modified butt actually) needs to be done with thickened epoxy. Wet out the areas to be glued ahead of time with neat epoxy. Then use thickened epoxy to bind them together. Epoxy is not a very viscous material. Particularly on a vertical surface.
 
E

e32stx

Member II
The method I described to you is not a buttjoint (I don't recall the gentleman's name whom this joint was named after). It does however start out as one but the wood to wood contact area is replaced by glass layup during the process as described in my earlier post.
I use 1708 because it's quicker to layup then just biax alone (less steps/time w/same results).US Composites carries 1708 suitable for epoxy at a great price.
When wetted out, 1708 can be moved around and handled where 1700 cannot making it easier to work with (as specialy for 1st timers). 1700 is great to but can be a PITA to work even for those in the know.
Picture are worth a thousand words so here's a sketch to show what I was trying to describe.

Cheers
Ollie
 

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E

e32stx

Member II
Also if ur doing the work now, be sure to have ur work area well heated as the epoxy won't cure otherwise.
Had I known, I would have given u the 100 lb propane tank I just got rid of.:rolleyes_d::rolleyes_d::rolleyes_d:
Pick up a propane heater at harbor freight (2 burner model works best) and rent the tank.
When u close yourself in to work, leave out the lower wash board for ventilation.

Nighty night
Ollie
 
E

e32stx

Member II
Don Casey's This Old Boat

This it a big project for anyone let alone a 1st timer. If you don't have any literature the I strongly suggest "This Old Boat" by Don Casey. It's about the best all encompassing book I've seen for the do it urselfer. You won't regret having it on ur shelf though it won't spend much time there because it'll be in ur lap most of the time ;-)
 
P

PDX

Member III
e32stx said:
The method I described to you is not a buttjoint (I don't recall the gentleman's name whom this joint was named after). It does however start out as one but the wood to wood contact area is replaced by glass layup during the process as described in my earlier post.
I use 1708 because it's quicker to layup then just biax alone (less steps/time w/same results).US Composites carries 1708 suitable for epoxy at a great price.
When wetted out, 1708 can be moved around and handled where 1700 cannot making it easier to work with (as specialy for 1st timers). 1700 is great to but can be a PITA to work even for those in the know.
Picture are worth a thousand words so here's a sketch to show what I was trying to describe.

Cheers
Ollie
Click to expand...


Actually I find 1700 easier to work with. It soaks up less resin, weighs less (both wet and cured), and has much better adhesion to a vertical surface when wet. It will require more layers to achieve the same build level, if that is a concern, but the end result will be both stronger and lighter.

Epoxy is a challenge to work with. Most people in the business who do things for hire will try to talk you out of using it. Different users have success with different techniques--particularly depending on what types of cloth and resin are used. Different runs of cloth, even from the same manufacturer, have different wetting properties. The working characteristics of different brands of epoxy can be strikingly different (although there is much better consistency within a specific brand than with cloth).

Finally, I would strongly recommend a trial project on a vertical surface, with the same materials you will use for the bulkhead repair, before you try the bulkhead repair. You might even be able to find some minor project on your boat so you don't feel like you're spinning your wheels.
 
M

Macgyro

Amazingly Still Afloat
Blogs Author
Payson Heavy glass joint

[h=3][FONT=Verdana, Arial, Helvetica, sans-serif]I think this is what you were talking about, and certainly looks like the way to go. The joint will most likely run from the bottom of the hull straight up to the cabin top. And it will be quite visible. I'm not too concerned about appearance, but it seems a shame not to attempt to make it look nice. I'll probably end up with some type of veneer across the entire bulkhead if I can find one to match.

I downloaded and read West System's user manual, and I'm pretty sure I can get a structurally sound joint using this method and the west system epoxy. I'll look into the different types of cloth, and may be able to procure some from the guy helping me get the right plywood.

In terms of timing, I may end up doing this earlier than I planned, so heat will definitely be used. I have an electric radiant heater, and can borrow a propane heater, but I'm pretty nervous about using one in an enclosed gas powered boat even with ventilation. I can also borrow an electric forced air heater, I just need to check the loads for the extension cord.
[/FONT]
THE PAYSON HEAVY GLASS JOINT...[/h]
plyjnt6.gif
Harold Payson did a little more work on the glass butt joint. I'm doing this from memory and hope I'm getting it right. To hide the build up of glass on a thicker sheet of plywood he recessed the surfaces roughly with a sanding disk in a drill. Then he added a layer of light fiberglass matt to the wood before pasting in the glass. Fiberglass matt is generally thought to provide better adhesion to wood than glass cloth although by itself it has little strength. Harold is big on using polyester resin on his boats instead of epoxy so perhaps the matt is more important for the polyester users. But you can see the advantage of the system: the final joint can be more or less invisible as the multiple layers of glass are recessed.

source: http://www.amateurboatbuilding.com/articles/howto/joining_ply/ply.html
 
M

Macgyro

Amazingly Still Afloat
Blogs Author
Bulkhead Joint

Ollie,

I'll see if I can find epoxy compatible 1708 from your source. Also, I didn't look at your sketches before posting, I didn't realize FRP would replace the entire thickness of wood. I'll see if I can find any other sources that can testify to the strength of such a joint. I would imagine that 3/4" of epoxy/fiberglass would be significantly stronger than the wood it replaces. My Dad and I were looking at doing something similar to close up a hole in the bottom of a boat, but we ended up not opening up the hole, so we never tried it.

Also, don't worry about my lack of experience, I have offers from experienced people to help me layup the glass, they just don't have the time to do all the planning for me and are tight lipped on giving advice on other people's boats. I'll get some good info out of them eventually, especially if I start doing something completely bass-ackwards.

-Dean
 
E

e32stx

Member II
Nice.
I use west systems. Not cheap but I like it. Some people like mas epoxy because it doesn't blush like other epoxy will.
If your buying from west marine, see if any of your buddies has a port supply account you can use. If they work in the marine industry they probably will and the bigger the company they work for the better the port supply discount.
I wouldn't worry too much about the propane. As long as you keep it ventilated ur good. Besides, I thought u chucked that galvanized fuel tank. If not, that would be on the top of my list.

Cheers
Ollie
 
E

e32stx

Member II
That's the joint! (Payson joint that is :cool:). The sketch was just to give u an idea, a visual if u will. FRP doest havvvve to replace the entire thickness.... but that's what I would do. The 1708 will make it a snap.
 
M

Macgyro

Amazingly Still Afloat
Blogs Author
Awesome Joint

Great! Thanks! I've got a gallon of West System and Fast Hardener, I will order the 1708 and wood this week, and borrow the heater. I measured the bulkhead, and think I can get away with replacing 2.5'-3' of the 4' width. I'm going to have to do part of the horizontal seat support too. The drawing below is my best analysis of the rotted area and the area I'm planning on replacing:

20131215_205805.jpg
 
B

Bobby Asher

New Member
Great thread. I just bought a 1970 35-2 (hull #116) and I'm starting on many of the same projects. Planning to have the port bulkhead chain plate repair done professionally due to time constraints but will be re-glazing and re-bedding all of my portlights before spring.

I also have some suspect engine plumbing that needs to be looked at before the boat goes back into the water.

Thanks to all for the great info/pictures.
 
M

Macgyro

Amazingly Still Afloat
Blogs Author
Professional repair

I'm sure we'd all love to see photos from a professional repair if you have time to post!
 
B

Bobby Asher

New Member
Macgyro said:
I'm sure we'd all love to see photos from a professional repair if you have time to post!
Click to expand...

Will do. The repair is scheduled for March so it'll be awhile. I'm also taking photos as I rebuild the Shipmate pressure alcohol stove and glazing/rebedding the portlights, so I'll post those as they progress too.
 
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