Floor Repair

[RoburMarine]

I recently purchased the boat pictured below on auction. It is a 1989 RENKEN 2688 SeaMaster. A lot of people have thrashed and trashed this boat but it seems like a nice boat to me. My problem is the rear area of the floow is spungy and I need to go in and replace the entire floor to make it right. Half the floor is a srew in fuel tank cover so I think building a new one will not be bad. I am at a loss for the rest of the structural areas though. Should I just go in and cut it all out and put in marine plywood and fiberglass? I am a novice at this and any help would be welcomed.

I am glad to have found this forum!!!!

Randy

[RoburMarine]

I have marked the SOFT areas with RED Xs on picture.

[H180DSC]

Randy,

Welcome, I don't know about your particular boat, but I have found that if there are soft spots in the sole, there are probably more structural issues underneath. ie: stringers and transom. These definitely need to be inspected for rot once you get the sole removed. As far as removing the sole, a circular saw with the blade set to the thickness of the sole works well, being careful not to go too deep and cut into the hull. You need to get the old sole out, and then start making decisions about how you will continue with your repair. Good luck!

Dan

[H180DSC]

I forgot to mention that there are a lot of posts on this site that deal with your specific problem. Most of these are due to poor craftsmanship by the original builder. It seems like the boat manufacturers operate on the idea that if its not a visible detail, then it is ok to skimp on it. If you are going to do this job, don't go cheap. Use epoxy and not poly, or you will be doing it again.

[mike steiger]

Hi,
I agree with dan about using epoxy to do the repairs. First off remove the large panel. Once removed you will have to take out the old core completely from the underside being carefull not to damage the top skin. If you measure the thickness of the core set your saw slightly less than that and make cuts perpindicular to each other, when your done it should look like a checkerboard then start to pull it up with a air chisel or by hand if you have to. Once this is done you will grind(36 grit disc) until you have clean fiberglass. To place the new core in (take a measurement of the old one ) mix up a batch of epoxy resin, milled fibers and cabosil to a thickness of vaseline, have the panel on a well supported flat surface( the top edge of the core should have about a 1/2 inch radius) and begin troweling on the mixture with a 1/4 notched trowel to both surfaces. Place the core in position and use cinder blocks or anything else to get the core pressed down. You should see adhesive oozing out heres where a piece of 1/2 inch pvc pipe will come in handy to make the fillets around the bottom of the panel with the glue that oozes out. Try to be as neat as possible about 32 oz of thickened resin sholud do it by looking at the photo.
Once this is dry you are now ready to apply your glass. You should be using stichmat (www.shopmanic.com/ U.S. Composites) if using epoxy. Start by laying a piece of 1 1/2 ounce mat wet out well(you will need a fiberglass roller) making sure it overlaps the original panel about 1 inche all around. Once dry you can then repeat the procedure with something like 1808db 90 degree overlapping that about 2 inches and then another layer overlapping at three inches, this should be plenty strong. When using plywood for a core be sure to prime the surface first with resin six hours prior to laying glass. Now your floor problem could be a sign of other thins going on but lets go on the premise that the water permeation is restricted to the areas you desribed thus resulting in the soft spots you feel. You must remove the damaged area back to where it is solid. This can be done with the method Dan described in the previous post. If possible leave a lip of about 3 inches on the liner floor to help you re-attach your new piece of decking, you can form a lip by scewing and epoxying pieces of plywood all around the perimiter to support you new piece. Once the bad section of deck is removed you can then measure and cut your new piece and attach to the lip and screw and epoxy together. Now you must grind back the existing glass on the floor to a feathered edge, once complete with that put a couple of layers of 1808, fair the surface flush and finish with something like interlux perfection with a non skid added to the mix. One thing about using epoxy when using fairing compound they must be epoxy base like system three fairing compound or they will not bond that well. I puchased my epoxy from www. aeromarineproducts.com great stuff competitively priced and the owner can explain to you any questions you may have. I hope this brief explanation helps.
Good Luck.

[mike steiger]

Sorry about the bad link for the fiberglass, the name of the company I use is U.S. Composites and the resin you want is the low visconsity 300 with the number 21 hardener available at www.aeromarineproducts.com.

[mike steiger]

Randy,
Any questions you may have I will be glad to answer.

[RoburMarine]

Thanks Mike!!!

I am sure I am going to have many questions as I proceed.

[Eagle Boats]

Mike, I have read a few of your posts. Thanks for sharing your expertise. A stupid question being that your last name is Steiger, and you are from New York, but are you with Steigercraft? I have always admired those boats.

[mike steiger]

Hi,
To answer your question I do not work for steiger, but I have done my fair share of work on them and own a 23 block island. I looked at your photo and my guess is that water got into your hull through the pie plates in that section of your deck. Most builder put some 3m 5200 or 4200 sealant and thats about it and after years of washing and water being on the deck it will find its way in and penetrate the core material. One wat to avoid this is to mark your holes where the deck plate goes and drill the holes oversized and backfill with a thickened resin. Once this is set up you can then re-drill for your screws and water can never permeate the hull. If I am correct that liner is not sitting on the stringers which could mean you have no problem there but the only way to tell is by openining up the area in question.

[rgaynor]

Anyone ever install aluminum sheet metal in a Jon boat for a deck? My floor and seat framing are already factory aluminum. I want to replace the fore and aft decks with aluminum, anything but plywood. It's too heavy. I have seen the Tracker Grizzly jon and it is just what I have been looking for.

[RoburMarine]

Mike, I got the middle panel over the fuel tank up last night and that was a job! They had all kinds of glue and mess in it. I see that the rot did in fact come from the Access port fitting as it seeped over time. I do not wish to reuse the old skin from the panel it is in horrible deformed shape. I would like to build a new panel. Looks like the panel is 3/4 inch thick and damn its HEAVY. Think I could go back with plywood and fiberglass using the old panel as a pattern? How will I get the nice topside texture? Gelcoat? Thanks!

[mike steiger]

You want to use the original panel because it is much easier to recore than fabricate a new one, take my word on this and I am sure this would be the consensus on this board. Just remove the old core the way I described in the previous post. Once you have done that secure the panel down to a flat surface using clamps and cauls than add a couple of layers of 1808 to beef it up some and now you are ready to re-core. If the panel has a crown in it to deflect water to the scupper valves, get the approximate differance end to end and clamp the middle down flat and shim up the ends of the panel to the necessary difference to form the crown. It is important to take the time to fabricate a lay up table to work on, this can be done with 2by4s and a sheet of 3/4 4by8 melamine covered particle board, this will help greatly while you are doing your work. Feel free to keep the questions coming, sorry I did not get back to you sooner but I have been a little busy.

[RoburMarine]

Ok Mike I took all your advice and the project is moving along. I was able to cut off the fiberglass layer easily with an air powered exhuast cutoff wheel that cut through it like butter! I then pried the entire piece off and exposed the soaked wood beneath. It looked very strange the wood was in 6x6 blocks 3/4 thick and most of it fell apart. I chisled what i could and am drying it out so I can grind the rest down to the skin. Ill post some pics when i get my camera working thanks for the help!!!

[mike steiger]

Hi,

Glad to hear that your making progress, those 6by6 blocks could be balsa core. It has been used in the industry for quite some time, light weight and once sandwiched between layers of glass you have a rigid panel. Keep up the good work.

[VKRUE]

Hello RoburMarine:
I'm not trying to intrude here... seems that you have expert advice from M. Steiger.

I just wanted to say one thing that has not been mentioned.
Quote by RoburMarine: I am a novice at this and any help would be welcomed.

I noticed 3 (three) access covers in your pictures. You'll want to be sure to include these access covers when you reconstruct your soles. The cover to the fuel tanks fittings is particulurly important... and required by USCG regs.

Might also check out those fuel tanks and lines while your under there.

[mike steiger]

Hi,
Ditto on that.

[mike steiger]

Vic,
When I retire I want to get my hands on one of those old mahogany Chris-Crafts some day and do a restoration on it. Good luck with your boat.

[VKRUE]

Hey Mike,
My boat is not a Chris Craft... I trust you realize this. It's was built in 1960 by a "KAUFFMAN BOATWORKS" in Ospree Florida. It's just a plywood thingy but, I'm in love with it. If I'm successfull in my efforts this boat will look pretty sweet with mahogany verneer on the topsides and a painted hull & cabin.

Thanks for the luck.

[mike steiger]

Hi,
I knew it was not a Chris-Craft, that is just the boat I dream of someday owning and restoring. I tip my hat to you for what you are doing and when completed it will look great. Good luck with your boat.

[mydauphin]

General Comments
Why do companys that make decent fiberglass boats put floors of wood that will rot?

That said, either enjoy boat AS IS for a while (Inject some can foam strenghten the floor or take everything out and do it right. Chances are that when start taking rotten wood out you may not have much left. Then do it right. It looks like you have some removal panels there. Cut wood to size then epoxy to present panels and seal everything tight with epoxy.

[VKRUE]

Mydaupin:
It's not that WOOD rots. Cheap, improperly prepared wood rots.
My boat is all wood. Built in 1960. The hull is in excellent shape as is most everything else. It's been around now for 47 years. It's seen a bit of abuse in it's history but, overall... it was in decent shape when I bought it.

Many companys that make fiberglass boats use less than top grade wood for things such as stringers because they are going to encapsulate the wood inside fiberglass at which point who cares about the wood. You'll never see it and it will last many years... but when it's gone...IT'S GONE. AND YOU CANT SEE IT EITHER - THAT IT'S GONE.

[mike steiger]

Hi,
To answer your question as to why wood is used in floor's, decks and transoms, if this was all done in solid fiberglass you would have a boat that would be so heavy you would not be able to power it, but if you could your fuel bill would be astronomical. Wood is a good core material if you take the time to seal things up right. One method is to mark your holes for whatever fitting you wish to install, drill the hole oversized backfill with thickened resin and once this dries you can then put you screws in to secure your fitting and the screw will have cured epoxy around the perimeter. When I install scuppers, transducers or anything else into a transom, I use this method. By doing this properly water will never permeate the core material. Remeber that most production builders will not do this. Short of a vessel having an accident this is alway the culprit when it comes to water damaged cores, but the beauty of it is that all this can be avoided if we take the proper measures.

[mydauphin]

Your both right and wrong. True, it is a matter of what kind of wood, its encapsulation and how it is treated. As far as weight, I have had may a boat with no wood anywhere. I had a 1979 Glastron that I got ride of all floor wood. It all rot away and instead of getting plywood again and glassing over, I used wood as template and made fiberglass panels with honeycomb thing with no wood. It was alot more work. but it is still good 20 years later.

The only place for wood for me on a fiberglass boat is stringer and transoms, and those should be high quality marine woods covered in Fiberglass and/or epoxy.

By the way on flooring, a neat floor to build is a composite of aluminum and epoxy. Light and strong.

Also found out that wood rots from rainwater/Fresh Water. Saltwater corrodes everything else but not wood.

[mike steiger]

Hi all,
I guess your only refering to the floor and not stringers, transoms, and decks/gunnels. Steigercraft has been building a solid fiberglass floor for about 13 years now. Their stringer/bulkhead system is also solid glass(1990),their absolutely bullet proof floor is the result of much engineering, time and money to do so. If your stringer system runs 1/4-5/16 thick the plywood core is not much more than a form for the laminate. Steiger is a great boat(semi-custom) but also not affordable to everyone. You can get a very good result with wood if the proper measures and good technique are employed. The compression strength of ply is also very good,I like composites, but they are expensive and may not fall into everone budget for a rebuild. If you figure a boat with a wood/glaass floor lasted 10-15 years and fitting were installed without the proper preventive measure taken it would never rot if the methods described above were used.

[naturewaterboy]

I also have a boat that has some soft spots in the cockpit floor, and more up on the bow. Are there any light weight options for coring that would cost the same or less than plywood?

[mike steiger]

Hi all,

You can use coosa nautical 20 its about 50 percent lighter than ply,Kledgecell,or balsa. Between the three I would say the coosa is the best,it will run you a little more than marine ply of equal thickness. Good luck with your boat.

[jimslade]

You may want to look into Nida-core. I don't like wood anywhere in a boat, especially stringers. Most older wood boat were made out of cedar. Old grow cedar takes a long time to rot.