Opening the belly of the Beast

Questions from a newbie fileting a whale. A 26 year old 22' Browning Aerocraft. I really enjoy the words of wisdom from all of you and I have learned alot just reading all the post for the last 3 years. However, I did not see any mention of my concerns regarding these..any input would be appreciated.

1. Can I just replace part of the rotten stringers?
2. I have read about spacing under the the stringer. Why do that?

Pictures:
Opening the belly of the beast and removing the flesh.
pic 1
pic 2
"Cutting the floor forward untill I reach good wood".... I may have to cut into the neighbors boat for that.

I have a multitude of fine color, from white to amber and moldy black.
Color of hull layup is light and dark in places, Why? is it Delaminated?
pic 3
pic 4

Browning Boat Mfg. was a bit skimpy on the foam fill..lotsa voids. Trapping water. I have 1000lb. of wet foam.
pic 5
pic 6

Checking cracks on transom..dangerous?
pic 7

Save the dry foam and fish finder and junk the rest of my boat?
Eric H

 

Wow, is there any un-rotting wood in there - I dont have experience with foam filling in wooden boats, but it seems like a real good way to trap moisture, and keep it warm, so that rot can grow... if it provides enough little spaces (like you show) to also provide oxygen... All the colors you see are probably different kinds of mold and rot. The black is probably the bad one - poke it to see if its soft under (wait! is there a fiberglass layer over the wood? Then be sure to plug the hole after you are done - if there is no real rot.). From the pics, it does not look too bad, and so if you can get to the wood, maybe some rot killer, and dryrot replacer will be what you need - if the rot does not go under structural parts where it might have affected the strength of the fastenings..
See what other say, but I would take the foam all out, and go for keeping it as dry as possible (ventilation) - heck, if you ever needed the foam to keep it afloat, its probably not worth saving anyways, so let it sink...
The space under the stringers is probably mainly to let water (condensation, etc.) not get trapped and form rot - but the foam kind of defeated that logic... stringers usuall sit ontop of the frams anyways, they are there for strength, so be sure they are good, and run the length of the boat - your engine beds too if possible (oh, wait, this is probably an outboard...). check also the strength of anything holding your shaft and rudder....
Are the cracks in the stern bad? I can not tell if they are in the wood, or the fiberglass or what. In general, back there, where your outboard engine is creating all those forces in every direction, yes, I would say its worth looking into very seriously. If there is no rot - in the hull or transom, then perhaps a block connecting the stringers to the transom will work.. always seal all holes, and places where you place wood against wood...
So, that is the advice of someone who reads a lot, but only has fixed up a few boats way in the past... take it for what its worth..
Cheers,
Grant

 

Hiya Grant, well she's a glass hull, and a 5.7 L I/O.. Now that I started removing all the foam I see NO way for any water to get to the bung hole to drain. it stayed trapped by the outer stringers. So the p.o. must have lugged all that (1000 lb.)
water around with him for quite some time. She probably did not plane well... And ofcourse since I just bought this boat, I found a ChrisCraft Stinger today and that's what I really wanted..aaaarrrgghhh.
Still hoping for more input on subject matter

 

This is actually a new re-incarnation of an old problem....

My boat isn't as sound as I thought it was, do I sell / trash it or carefully re-build it?

There are a number of answers on this, but take it from someone who has done it the hard way (repair), it is expensive, stressful, fun and worth it. The first thing to do is to get the boat "Stable". The easiest way to do this is to remove everthing that's obviously rotten and photograph it as you do it. then either sit it on the trailer, or build a stand for it and put up a tempory shed over it (22' won't fit in a standard double garage).

The last thing you want is water getting in as you repair it.

When you've got all the rubbish out, then you are in a good position to start re-building the rotten parts that you stripped origenally. There are a few rules for this...
1) ALWAYS go back to clean, dry material, be it wood or GRP. (Use of a wire brush on a drill will help here)
2) ALWAYS use the same resin system. Polyester or Epoxy, don't mix them. (Some smartarse will point out that you can)
3) Do what you can to use the same type of laminate as the original. It's pretty unlikely that the laminate was wrong

Other things to bear in mind are...

1) Strip as much as you need to in order to get a good repair.
2) You shouldn't really need the foam, it's probably there for sound-deadening purposes. It might be worth checking with USCG to see if it's needed as reserve bouyancy (if so try to use inflatable bags).
3) Stringers should really extend to the transom (as if you were building a proper frame-and-stringer boat). They rarely seem to. I would certainly extend them aft and stiffen up the transom generally.
4) Also check the engine bearers, rot or delamination there would be a pain. (it is possible to lift the engine, repair them and re-seat it).

Good Luck, I hope this helps feel free to e-mail me if you need more help,

Tim B.

Tim@MarineDesign.tk

 

Made some progress removing the wet foam
Posted some pictures without the smell...

 

I would remove everything inside and do a re build.

 

Shape....

Assuming you do a rebuild:

Keep in mind that when you pull out old structure things can/will sag and twist. Make sure that you support the hull well and evenly and measure/eyeball for symmetry and fairness. IF not you may replace structure only to find that you have 'built-in' sag/twist/bumps/etc etc.

 

AH the saga of "Opening the Belly of the Beast" continues....
Still In process with opening her up, I have discovered more strange things. One thing I discovered is that at 60 it's hard for this ol' fart to do much anything in this heat.
But the will to "get er done" and "done right" is prominant. BUT, I will never do another floor !!!
The young farts that are suppose to help have all disappeared. Funny how that happens with the young ones of today.http://www.boatdesign.net/forums/images/smilies/mad.gif


Below is a Pic of the main stringer and engine mount(s) stringer(s). both sides the same.
Pic 326
Arrow 2, points to an area that has no drain to the bilge on either side..is that normal? 3" of water stays trapped there.
Arrow 3, has the fibergalss pulled away from the stringer and has original foam between it and the lumber. Not my doing. great craftmansship.

Also the 1/2" pvc pipe that runs to the bilge under the engine is clear of debris since I ran a 18' gun brush type affair in it, from the drain hole in the transom.
However, as you can see from the pics 2 & 3 (below) there is standing water trapped in the compartment between the gas tank and cuddy. The foam was wet for the lower 8"
Pic 324 compartment 2
Pic 327 Dry Bilge
Here's why.
The next pic has all the foam and water outta there..there are NO holes in the 1/2" PVC..should there be? I would think yes.
Pic 336a, Pic 338
Else, (as now) the PVC pipe will only drain from the bow of the boat just under the cuddy well, to the rear. Doing nothing inbetween.
I would think that if this were a perferated piece of PVC, this boat would never have had it's foam/water retention problem.
Is my assumption correct?

I have not removed the tank yet, it's full, 90+ gallons of old gas. Don't quite know what to do with it or where to put it...suggestions?
I am sure there is no drain in that compartment either. The PVC pipe just runs underneath the tank in a solid hole free piece.

Another strange thing is the main stringers do not have any weep holes leading to the bilge either.
I would think one hole or relief should be close to the transom, so that any water can drain to the bilge......Correct?

Comments Please.

Eric H, old, tired, hot, wet and full of FB.
work in progress

 

Regarding the PCV pipe, I am guessing that at rest the boats hull loq point is at the bow, and the idea is that anywater trapped there will be drained to the transom drain hole when pulled out on a trailer (or planning, if you dare remove the plug then ;-). Is there a bildge pump? Thats where water should be able to flow to. Thus a hole inbetween might just move the water to the wrong place location and leave it there - but am not sure. Maybe that line of thinging helps you out.
I would say, if you are not going to replace the foam, then the best bet is to just create holes under the stringers and any frames, so the water always drains to the center, and can drain to the 'low point'.

 

Yes it does have a bilge pump albeit it was a very small unit located in the bilge under the engine. Draining all compartments to the lowest point was my thought also. I just can't believe the mfg would have built this boat this way. Perhaps the thinking was wherever the foam is it would displace the water 2 items cannot occupy the same space..wrong! Air pockets in the foam can hold water and will.
I am not going to take the floor up in the cuddy. the foam under there is dry. T.G. I have finally found some dry lumber and foam.

 

Take out your tank and inspect it, you will probably need a new one. Sam

 

Great read here. I im in the midst of a similar rebuild. I too had a odd problem of the outboard sections of my stringers was totally waterlogged foam. No way for it to escape. Same as the bow.Enclosed water soaked foam. I was also wondering about adding drain holes leading to my motor well drain or running tube through the midsection locker to the drain.

My boat is not nearly as larger as yours (16ft invader with OB) Every piece of wood was rotten and soaked. The floor was so rotten it had turned to dirt and had a tree growing in it. I am just getting ready to replace stringers and transom then put the floor back in. With 104 degree weather it has dired out well. But unfortunately for me all the wood had to go beyond repair.

 

Hey Trav I would keep that tree handy, It's roots may help suck up some water.
Sorry, i just had to say that.
I'm cutting in limber holes or running 1/2" pvc pipe from each isolated compartment and the deck to the bilge. My stringer boards are at least 1/2" above the hull and tabbed in pretty good. I just can't imagine why the mfg. did not leave a bit of space (between tabs) to let any water run to the next lower level and into the bilge. Had they done that, my boat would still be in fine shape and usable today! It's no wonder Browning Boats (Aerocraft) went belly up, With cheap design and poor workmanship they couldn't survive.

100+ Degree heat is right, I can't get anything done. I have a breathing problem and it kills me just climbing aboard in this heat.

Eric H
Rebuild in Process

 

Limber hole are very important in hull design great care is taken in the design stage to ensure the limber holes are placed correctly so that any water can drain to the removal point when the boat is at rest or in motion you will need to put a lot of thought in to their placement other wise history will repeat its self
Alex

 

I have to compliment you on your attitude and on the completeness with which you are documenting this project. In response to some of the questions in your posts:

1. The hairline cracks in the transom area (pic from your first post) are likely just in the gel coat that was applied to produce a finished apperance to the mechanical area. This type crack is likely to be found in other spots on a boat this age, and are not structural. You've got better things to worry about.
2. The multitude of colors in your fiberglass is somewhat more worrisome. The factory resin used to lay up your hull had a red dye in the catalyst that results in the dark red/moroon color you see. The more yellow FRP looks to be resin with no dye used on glass that was applied afer the hull was cured. In other words, it looks like the MFG layed up the hull with dyed resin, and later "taped" in the structural members using a resin with a clear catalyst. The white portions and black portions of the FRP are a concern. The black is likely rot and usually if you dig around on it, there's little resin left and the black is moldy fiberglass material. Any fiberglass that is frayed, wet, black, or has pockets under it needs to be ground down to good material, and patched. I don't know what the white color is the result of - could be many things, does it feel the same as the red colored glass? Does the white color come off when scrubbed? Hate to say it, but your photos show a boat that wasn't very well designed structurally - I'm sure that's not news to you at this point.
3. Get rid of that foam! It only serves to hide areas that shouldn't be hidden, and cause way more problems than it solves. I work for an organization that is producing 26ft FRP boats that cost over $100k, and guess how much foam we but in the boats...zero! Foam is a cheap way to hide poor construction and market "unsinkable" boats. You don't need to fill your hull with foam, and it's in your way.

There is some good advice above, especially from Tim B, and the caution regarding keeping the hull form true during the rebuilding of the structure. It's important to get this boat clear of entrapped water. Anywhere water is trapped it will freeze in the winter, expand, and cause all sorts of problems. Always, always, always seal any wood that your intending to put back into this boat with resin after it's shaped and before it's installed. If you're going to use any plywood, it really needs to be marine grade, which is expensive. you've got lots of work ahead, but it will be nice to have real ownership of this boat when its done!