1989 Ski Brendella (boat restoration progress)

[HiltonFerg]

Re: 1989 Ski Brendella (boat restoration progress)

I've been drying the stringers as much as possible. I put them on their edge on top of some other wood with a space heater blowing between them. I turned the boards or moved the heater every hour or so each evening since my last post. During the day I replaced the heater with a 24" fan. They're dry enough.
Today I sanded them on all four sides and completely wrapped them in fiberglass.

I banged my head on the board. Now I have resin in my hair.

 

[jigngrub]

Re: 1989 Ski Brendella (boat restoration progress)

Don't rush the stringer installation, as others have said you should cut the walls to the old pocket off and grind back to new glass in the pocket and 3-6" on each side so you get a good bond when adhering the stringers to the hull and tab them in with new glass.

Keep an eye on those resined stringers, if the resin turns milky they weren't dry enough and the resin didn't penetrate and it won't bond. You may want to consider just using those PT stringers for something else and buy some nice dry fir stringers, they'll be lighter and straighter.

 

[HiltonFerg]

Re: 1989 Ski Brendella (boat restoration progress)

Here are a couple dry, daylight pictures.

I really hope they're "good enough", because this is as good as they're gonna get. This "free boat" is costing me a fortune. I'm gonna sand them and there are a couple areas I'm going to cut off and redo, but they are done for the most part.

If you look closely you can see grass, dirt, and pine straw in the stringer furthest from the camera. That's from where it fell on the ground. Cursing ensued.

Believe it or not, I was sober when I glassed these.

 

[HiltonFerg]

Re: 1989 Ski Brendella (boat restoration progress)

Nope. Not good enough.

There should be a sticky somewhere on this forum saying not to use pressure treated wood for stringers. The first I heard about it being too wet was about a week ago in this thread.

Now I'll buy some non treated, use the ones I've already cut as templates, glass them, then put them in.

Wasted about $100 and a more valuable dozen or so hours.

 

[Friscoboater]

Re: 1989 Ski Brendella (boat restoration progress)

There was a bunch of talk a while back about it. I think those chemicals prevent the resin from sticking. Make sure you grid those tabs of glass down and start all new. Space the stringers off the hull about 1/4" and then use two layers of 1708 is separate widths to tab it in. then go over the top with a couple of layers of 1.5oz CSM.

 

[Woodonglass]

Re: 1989 Ski Brendella (boat restoration progress)

Have to Checked the first link in my signature below. Lot's of details on stringer fabrication and installation.

 

[mrdjflores]

Re: 1989 Ski Brendella (boat restoration progress)

+1 to what WOG said....read this his information on stringers...
laminated layers of plywood work best and is what most people use...
a good exterior grade (non pressure treated) plywood

 

[Auger01]

Re: 1989 Ski Brendella (boat restoration progress)

Nope. Not good enough.

There should be a sticky somewhere on this forum saying not to use pressure treated wood for stringers. The first I heard about it being too wet was about a week ago in this thread.

Now I'll buy some non treated, use the ones I've already cut as templates, glass them, then put them in.

Wasted about $100 and a more valuable dozen or so hours.

I have spent many an afternoon behind a Ski Brenda running a slalom course. I think its great that you are fixing the old girl up. With that being said, I hope you dont try and slide the stringers into the old pockets. Both WOG and FriscoBoater (not to mention little old me) think its a BAD idea. Do it right or do it twice.......

 

[HiltonFerg]

Re: 1989 Ski Brendella (boat restoration progress)

I've read the link WOG mentioned and watched ALL of FriscoBoater's videos. I feel like I know the guy personally.

I have a friend bringing over wood for the stringers hopefully today.
Fir was surprisingly difficult to find in the size I need. I finally found it at a small lumberyard. I tried to pick them up Saturday, but they are only open during the week. Waste of a trip and a favor.

I don't understand the reason for cutting off the "pockets" entirely.
The hull is fiberglass and the pocket is made of fiberglass.
There is going to be a mechanical bond (as opposed to chemical) anyway, all that leaving a portion of the pocket material will do is move the area of mechanical bonding from one place to another.
My plan as it stands is to cut the pocket down to ~2", put the wood into the gap left.
The wood at this point will already be wrapped in fiberglass, so there wouldn't be a chemical bond there anyway.
I see many people using "peanut butter" to "fillet" so that that glass has a smooth transition from a vertical position to a horizontal position.
Leaving the "pocket" will already provide a nice transition.

Basically cut the stringers, wrap them in fiberglass, use an enormous amount of PL adhesive, clamp and allow to dry and "outgas" for more than 3 days, sand the areas where the new fiberglass will attach to the hull, use progressively wider strips of fiberglass*, then a really large piece of fiberglass*

I don't see why that wouldn't work.

 

[Tthomp3]

Re: 1989 Ski Brendella (boat restoration progress)

it will not be strong enough because the pockets are not providing any structural support. the pockets will not be bonded to the wood so the point where the stringer is bonded to will be higher up the stringer instead of at the base where all the stress is

 

[HiltonFerg]

Re: 1989 Ski Brendella (boat restoration progress)

I still don't understand. Why would they not provide the same strength they did on the original piece of wood?
Assuming that the wood I install is already wrapped in fiberglass; the resin won't soak into the wood anyway.
The stringers would be "stuck" to the hull with resin, and I don't see how that would be different from sticking the stringers to the hull with glue. The plan is still to completely envelope the stringer with fiberglass and extend it 12-14" onto each side of the hull. We are really only talking about ~2" of sidewall. As long as there is plenty of adhesive, I see no reason it wouldn't make full contact with both the hull and the small vertical area of the channels I plan to leave.
The original stringers lasted 23 years, and they weren't wrapped in fiberglass. I only want to get another 23 years out of this boat. In 2035 I'll be ok doing this again.

 

[jigngrub]

Re: 1989 Ski Brendella (boat restoration progress)

You've got to grind the 23 yr. old crap and corruption off to get down to good clean glass and resin... and roughen up the surface to ensure a maximum bond.

You've got to grind from the centerline of the pocket out 4" on each side for an 8" wide strip the length of the stringer. If you try to glass up on what's there without grinding away the old glazed surface and roughening the surface you won't get a lasting bond and those stringers will break free.

 

[Galentheboatkiller]

Re: 1989 Ski Brendella (boat restoration progress)

Hi everybody, I am the ******* who dropped this project on Hilton. If I would have had any idea this would be this big of a project, I would have never given him the boat. I guess no good deed ever goes unpunished!

I talk to Hilton just about every day and we discuss the progress quite often. I only wish I was there with him to move the project along. It really sucks to work on a project by yourself, but is actually enjoyable when you have help. I do have some questions and joined in on the discussion after Hilton asked me to. I am not trying to be difficult, I just really want to understand the reasoning behind the suggestions. I have never worked on fiberglass, so this is really a crash course in fiberglass repair for me.

As I understand the process, after the stringers are cut, Hilton is to soak the stringers in resin to get it to soak into the wood and cure. I assume this is to aid the soaked fiberglass matting with bonding to the now resin treated stringer wood. As a secondary product, the resin also helps protect the stringer from the moist environment that is going to be present in any boat. Please elaborate if I left anything out on the reason to soak the stringer in resin.

The next step I want to understand is the using adhesive to join a bond between the stringer and the original hull of the boat. I assume the process would be to rough the existing fiberglass and apply the adhesive between the stringer and the fiberglass base and allow curing time. How great is the bonding strength of the adhesive Hilton chose (sorry, I don't have the brand of adhesive handy, I am sure Hilton can chime in on this one) compared to that of fiberglass. Would the adhesive bond be better if the stringer was not soaked in resin prior to bonding the stringer to the fiberglass hull?

The last question, and really the reason I joined in this discussion, is the idea to remove all of the existing pocket. On one hand, it makes complete sense, and on the other it makes no sense at all to me. Does anyone here actually know how well the adhesive bonds to existing fiberglass? If the adhesive used will create a bond roughly equal to the new fiberglass bonding to the existing fiberglass base, then the existing pockets would actually be an advantage to keep, as to maintain as much original structure as possible. Also, I would think the new fiberglass bonding on the outside of the pocket would have better mechanical retention and less torsional stresses then if you remove the pocket and have to bond to the bottom of the boat. This is of course assuming that I am correct in that the function of a stringer is to strengthen front to back and not as much side to side in the boat.

On the other hand, if the adhesive is not nearly as strong (torsional strength, shear strength...ect) as the fiberglass to resin bond then I see absolutely no reason to even consider the use of any adhesive at all. Why not simply cut off all the existing channel, rough up the original fiberglass and build up the areas where the stringer does not contact the existing base fiberglass of the boat with a few extra layers of fiberglass to fill the gap? This would remove the weak link of the adhesive along the bottom of the stringer. Also, the removal of the pockets, at least in my mind, necessitates that the new fiberglass bond with the existing fiberglass is absolutely as strong as the original fiberglass to fiberglass bond was. I simply have no idea if this is possible.

Another question I have is how does everyone on here seal the areas where the bolts go into the stringer. The stringer isn't going to be exposed to moisture anywhere except where the holes are drilled through the fiberglass for the bolts. I believe that Hilton will attest to the areas rotted where in the areas of the bolts.

Last, I really believe we are actually splitting hairs over methods. Has anyone actually seen a stringer bond fail and come out of a boat? Somehow, I imagine it doesn't happen very often. In fact, I imagine there are many boats out there with rotten stringers that have no idea and perform perfectly fine. If Hilton would not have found the problem, he would probably have never had a problem with the rotten stringers sitting in there.

I am sorry for the long post, but I really do appreciate the help of those who respond to help both me and Hilton understand the mechanics of the stringer repair.

Galen

 

[fat fanny]

Re: 1989 Ski Brendella (boat restoration progress)

In other words you need to think of it like this. The hull is your body and the stringers are your skelleton and if you took your body into a game like Football for example how long do you think your body will last without a strong bone stucture. Why chance it why put anyone at risk when it can be repaired correctly for your lifetime if done right.

 

[jigngrub]

Re: 1989 Ski Brendella (boat restoration progress)

It's Hilton's boat and he can d it anyway he wants, we're just trying to help him with the best advice.

Reading and looking at the pics and vids in the other fiberglass restoration threads is really the best way to learn about this if you're really interested in it.

You can see the practices and procedures that make a successful restoration and a beautiful and seaworthy boat... and you can learn from the mistakes others have made.

As far as your question on adhesion, the bond from new to old materials is strictly mechanical... and that requires a roughened surface that is clean and fresh. You'll see this in every fiberglass restoration thread.

The biggest thing about restoring fiberglass boats is you want to do it right the first time because it's a huge amount of work and money, and if it has to be taken apart and done a second time the time triples and the money at least doubles. I don't think Hilton wants to ride around the lake with the deck and stringer rattling around in the hull and the hull flopping around every time he crosses a wake.

Take the time to read some of the other restoration threads.

http://forums.iboats.com/boat-resto...lly-started-w-pics-384982-25.html#post3586813

http://forums.iboats.com/completed-...gnature-deck-stringer-restoration-510077.html

http://forums.iboats.com/boat-restoration-building-hull-repair/78-ebko-lebaron-therapy-524704.html

http://forums.iboats.com/boat-restoration-building-hull-repair/my-project-74-ebbtide-584261.html

http://forums.iboats.com/boat-resto...om-deck-stringer-replacement-help-471173.html

 

[HiltonFerg]

Re: 1989 Ski Brendella (boat restoration progress)

I guess the biggest question is "How well does PL Adhesive bond to fiberglass?"

If the answer is "fantastic!" than the choice is clear.

I'll wrap a 2"x4" in sandpaper and scrub the inside of the channel, then wipe it down with acetone before gluing the fiberglass wrapped stringer into the fiberglass channel. Clamp that, let it dry, out-gas for >72 hours, then sand ~6" on the outsides of both stringers and the vertical portion of the shell that remains.
Wipe that down with acetone, then fiberglass with strips of increasing widths; eventually completely enveloping the stringers.

I have contacted Loctite and posted a link to this thread.




We have a discussion on an internet forum that I would like some professional advice on.

http://forums.iboats.com/boat-resto...endella-boat-restoration-progress-575658.html

It's a relatively long thread, but I think it's interesting. If you want to skip to the part relative to Loctite it's on the second page.

I'd love it if you created an account and responded.

Thank you in advance.
Hilton

 

[jigngrub]

Re: 1989 Ski Brendella (boat restoration progress)

If you want to see how the PL bonds to fiberglass squirt a small bead on the inside of the hull in an inconspicous place (where you're going to install foam would be a good place) and let it cure, then come back with a putty knife and try to remove it.

If you're wanting to leave the channel to hold the stringer in place while you bed it in with adhesive you can cut most of the channel away leaving 1-1/2" wide pieces alternating from left to right side and 2' on center. This will enable you to do the grinding you need and still hold the stringer. You can come back after the adhesive for the stringer has cured and cut the tabs off or glass over them.

 

[Galentheboatkiller]

Re: 1989 Ski Brendella (boat restoration progress)

jigngrub, thanks for the links! I honestly spent about 8 hours last night (work nights and it was Sunday for me) watching Friscoboater rebuild his boat. If he is ever in Biloxi, I owe him a beer or 3! The only thing I would have loved to see a video of was him leveling out his stringers in the boat. I can't cut a straight line with a skill saw on saw horses...I have no idea how he did that good of a job laying on his back!

As for the new to old fiberglass bond, I actually lean towards it is actually a chemical bond. Wiping with acetone(which is really an excellent volatile solvent) would alter the cured resin allowing the new resin to bond chemically to it. This leads me to feel the new to old fiberglass bond is much stronger than a simple mechanical bond would be.

Thanks to the videos, I understand (which I didn't earlier) that the stringer should never touch the bottom of the boat. I have already discussed this with Hilton along with a plan to ensure this doesn't happen.

I was actually amazed that the stringers in Friscoboater's boat were just 1/2 inch (or maybe 5/8) plywood. This leads me to believe that the main forces that the stringers are designed to take are front to back, and not so much side to side. Due to the direction of the forces applied to the stringers, I feel, as Hilton does, that the PL adhesive will hold exceptionally well. While I understand your test to see how well it adheres, I feel a better test would be to bond a piece of fiberglass to a board and try to pull them apart lengthwise, and not simply try to pry them apart.

The real question isn't whether the adhesive will be strong enough initially, but how the adhesive will hold up over time as it completely cures. This, I honestly don't know the answer to.

Honestly, to me, the main advantage of using adhesive to hold the stringer in with adhesive where the boxes currently exist really comes down to being able to bond the fiberglass going over the stringer to the vertical surface of the existing box versus the horizontal surface of the bottom of the boat. This would bring in the sheer strength of the vertical bond versus the pry (for lack of a better word right now) of the horizontal bond.

On the other side of the coin is to completely remove the boxes the original stringers rode in and completely reglass the area as Friscoboater did. Hilton is already going to have to do this where the boxes have already been removed. This means that the direction Hilton is leaning towards right now is really not saving either time or money. The added benefit of removing the boxes is, from the evidence that I have seen from being on this forum for a very short time, we know that it works. It will also allow Hilton to cut his stringers much closer to the actual profile of the hull, allowing a much more consistent layer of PL adhesive at the bottom of the stringer. This adhesive is now not really used as an adhesive, but more as a shock absorber to ensure the wood of the stringer doesn't cause a flex point and crack the hull.

I just got off the phone with Hilton (he really is a brother to me) and he talked to an engineer with Locktite about the PL adhesive. I will let him get into the details, but I really feel much better about the adhesive properties and longevity. I was starting to lean towards removing the boxes completely, but now feel good about Hilton's plan of action.

Sorry for such a long post, but this has also allowed me to think this out as I type the post. Sort of like a pros and cons list.

Thanks again for the links and the valuable knowledge!

Galen

 

[Galentheboatkiller]

Re: 1989 Ski Brendella (boat restoration progress)

Another quick question, does anyone know the consistency of the cured PL adhesive? I am really curious whether it is pliable like silicone or rock hard. I just don't have any here and don't want Hilton to open a tube before he is ready to use it and figured some of you have had some spillage and would remember the feel of the cured product.

This would answer my question as to whether it is used as a shock absorber or makes a hard seal completely across the area of the stringer.

Thanks again for your help!

Galen

 

[jigngrub]

Re: 1989 Ski Brendella (boat restoration progress)

If you grind and then wipe with acetone you get the best of both bonds.