DECK, AND STRINGERS, AND TRANSOM? OH MY!

[Daniel1947]

I am sure there are enough photos of rotten decks, stringers and transoms on the forum; however, if anyone wants to see mine, I will post them. For now I would just like to post the photos showing my area of concern as I continue rebuilding my 89 Astro Quickfire 18FS. I have already removed the cap and cut out decking and stringers; I haven’t really started the grinding yet but have done some. My area of concern at this point is the transom.

I have removed the main stringers to within a few inches of the transom. I drilled holes near the bottom of the transom as is indicated by the “YELLOW” circles. Even though the stringers and deck was pretty rotten, and the foam was still wet, all I seemed to get off the drill bit was “dry” powder wood. I must also add it was very hard, drilling into the transom, so I am having my doubts if the transom will need to be replaced.

 

[Daniel1947]

To continue....sorry.

~~The “RED” circles show the ends of the two main stringers. As it can be seen, the ends are “dry” which leads me to believe (and hope and pray) that the transom is indeed solid.
My plan at this point in relation to the transom is to remove the rest of the stringers; and remove the horizontal brace/support as well as the two vertical supports (indicated with “RED” circles in next photo); then remove the fiberglass by sanding and grinding the transom all the way down to bare wood; and then re-evaluating the transom.



If the transom is dry and in good condition, I see no reason to go through the trouble of replacing it. I will just lay down a couple layers of CSM, 1808, etc. I do however bow to the expertise of fellow forum members…so…What do you all think?

 

[greenbush future]

If you don't have any rot in the transom (drill test) why are you removing the inner skin at all? Seems like extra work and $ too me. You could replace the stringers and be done I think.

 

[jigngrub]

My plan at this point in relation to the transom is to remove the rest of the stringers; and remove the horizontal brace/support as well as the two vertical supports (indicated with “RED” circles in next photo); then remove the fiberglass by sanding and grinding the transom all the way down to bare wood; and then re-evaluating the transom.

If the transom is dry and in good condition, I see no reason to go through the trouble of replacing it. I will just lay down a couple layers of CSM, 1808, etc. I do however bow to the expertise of fellow forum members…so…What do you all think?

Sounds like a real good plan.

Removing the inner skin will give you a pretty good idea of what you have and will let you tie the stringers back in the way they're supposed to be.

 

[Woodonglass]

If in fact the transom is yielding dry shavings at all locations then I'd recommend just grinding the inner skin down to fresh glass at the locations where the stringers will be attached. There is absolutely no need to replace the total skin. Total waste of time, material, and money IMHO!!!

 

[Daniel1947]

Greenbush, Jigngrub and Wood....thanks for the input....I was only thinking of removing the inner skin to completely verify there wasn't any rot. Not to bring up any unpleasant thoughts...but I had a biopsy of the prostate once because of high PSA...when they got done sticking me 10 or 12 times, I asked the Doc if they all came back negative then I didn't have any cancer (rot)...the Doc said, "well not really, if we didn't hit the cancer cell we won't know for sure." Kind of what I was thinking about the transom. The deck and stringers were really in pretty bad shape, foam was soaked, and I was surprised when I got the dry shavings from the transom. Just concerned that maybe I didn't hit the right spot.
I guess I will remove the horizontal support and the 2 verticals and see what it looks like with the rest of the stringers removed. As always...thank guys for the info, I can always count on the Forum Family.....Now if they will just get the website fixed and back in good shape.

 

[jigngrub]

.I was only thinking of removing the inner skin to completely verify there wasn't any rot. Not to bring up any unpleasant thoughts...but I had a biopsy of the prostate once because of high PSA...when they got done sticking me 10 or 12 times, I asked the Doc if they all came back negative then I didn't have any cancer (rot)...the Doc said, "well not really, if we didn't hit the cancer cell we won't know for sure." Kind of what I was thinking about the transom. The deck and stringers were really in pretty bad shape, foam was soaked, and I was surprised when I got the dry shavings from the transom. Just concerned that maybe I didn't hit the right spot.

That's the way I took it and I still think it's a real good idea.

Even if you were to drill 100 holes with that little drill bit you'd still only be sampling1% or less of the transom.

Reglassing the inner transom skin isn't going to be that much time or money and it'll be well worth it for the peace of mind.

 

[redneck joe]

all I seemed to get off the drill bit was dry powder wood.

shavings or powder? That will mean a big different in your approach

 

[kcassells]

On another not, sometimes the high speed drill method produces heat and the wood powder "appears" dry. Try if you want, to use a 3/4" hole saw or larger and retrieve the wood that way for inspection. If it's good you can just PB it back in.

 

[Daniel1947]

Redneck Joe.....kind of a combination of both. I know as rotten as everything else was I was surprised how hard it was to drill into the transom. In truth...the shavings were probably wood and the powder was a mixture of resin and wood....but it all seemed to be dry. Appreciate the input.

Since I plan on sanding/grinding the hull to remove old resin and glass tabbing, and rebuilding it better than factory, I am really leaning towards removing the skin and making absolutely sure. I have a local supplier that carries all the materials except for 1708...they carry 1808, about $1.00 a yard cheaper than 1708. Once again...Thanks to all for the input.

 

[GT1000000]

Howdy Daniel,
Glad to see you are back and at it...
I am definitely on the fence as to which direction to go...
By the looks of the pics, they must of used some really good quality, disease resistant hard wood in the original construction because from this distance the remaining sections of knee stringers look fresh.
The reason I would be on the fence is to have gone this far and not replace the transom, although I completely see your point about it both looking good from a few drillings and the possibility that you just haven't hit the right spot to find rot...
My only argument in favor of going ahead and replacing the transom is the cost of doing so would probably only increase by a couple of hundred bucks and you would then be sure that all the bones are brand new...however, the amount of additional labor is quite the turn off...
I can only sit back and see what the rest of the tear down reveals and continue to hope the transom is as solid as hoped...
Regards,
Gus

 

[Daniel1947]

Thanks Gus....Kind of where I am at really. I have watched your rebuild of Bassassin as well as hundreds of others on this site. I want to do the job right, but see no reason to make more work than necessary. As I did the tear down on the Astro, it seemed that every piece of wood was rotten, the wood strips in the chines, the two inner stringers as well as the bulkheads and main stringers. Every piece of wood showed signs of rot, However, I was really surprised when I got the main stringers cut back within 6 inches of the transom and as can be seen in the photos....they weren't rotten. Up to that point, I had it pretty much decided that I would end up replacing the transom also. But, for now I think I will remove the braces and the skin and see what I have. Just a follow up for everyone's information, I am retired - so I have the time, I have already allocated the funds and shopped for prices, so it isn't really a decision based on money or time or the amount of work. Heck, it is only in the low 90's here; a little sweat won't hurt me too much. :flame:Thanks again everyone.

 

[Woodonglass]

My experience tells me that a series of 1/4" holes space 4" apart drilled across the bottom of the transom approx 4" above the hull that yield dry shavings are indicating a "Good to Go" transom That's what I did with my 48 yr old transom and she's still going strong. Drilling into wood with a 1/4" bit will NOT generate enough heat to dry out WET WOOD!!!! If it's wet You'll be able to tell immediately. As I stated previously. The time, effort and dollars associated with removing and replacing a perfectly good transom is not IMHO worth it. But, like I always say...It's your boat and you're free to do as you see fit. Like GT1000000 says It's about a $300 project and about 10-12 hours worth of work.

 

[Daniel1947]

A lot to consider, but since I am grinding from the bow to the rear, I have some time to consider all the information before getting to the transom. I am leaning hard towards removing just the rest of the stringers and also the braces, sanding/grinding the areas that will necessitate clean surfaces for attaching and tabbing new stringers and braces, then seeing what I have. The skin may not need to be removed from the transom...but it is kind of ugly....lol. I have a heavy duty, professional, body shop, Black & Decker 7" high speed grinder. I started on the hull with some 24 grit "paint buster" discs....quickly realized that was too aggressive...am now using 50 grit and they are doing just fine...have a 4-1/2" grinder and 40 grit flap wheels for getting into the tighter areas...the rest of the hull is getting there. I believe the B&D 7" will do a quick job of getting the transom skin removed if I decide to take it all the way down to bare wood. Thanks again everyone...I will keep posting as I continue, I already have some additional questions, but they can wait for now.

 

[Daniel1947]

~~HAPPY 4TH OF JULY everyone...if you're on the water...stay safe. I have sanded/ground the skin off the transom...found a few spots in lower corners that showed evidence of rot. So, I removed the whole transom. I hate to say it, but the whole transom came off in one complete piece, just a little prying. Some wood still stuck to hull, but I guess I just got lucky. The transom was not attached to the hull at the outer edges - red circles/areas.



I had already removed the flotation foam - purple circle from both sides. There is/was a gap of approximately 1/2 to 1" between the edge of the transom and the outer hull, port and starboard. After I ground the skin off the transom, I dug out additional flotation foam aft of the transom between the hull - yellow circles.



I apologize for the lack of clarity on the photos, I should have taken one prior to removing the transom. After I removed all the foam between transom and hull, I discovered that the transom was not even attached to the rear hull except for right in the center - blue square.





Only thing supporting the transom on outer thirds- yellow areas - was the foam. It was not attached anywhere in the yellow areas.
My plan is to attach the new transom not only in the center - blue areas, but also all along the outer edge of the hull red areas. This will require the new transom to be approximately 1" longer (wider) that previous. My thinking is that the additional bonding to the port and starboard hull will be a good thing. I will probably go back to filling the area between the transom and rear of the hull with flotation foam.

The plywood is 1-1/2" thick, it may be a little strange, but I can save $4.00 by purchasing a sheet of 1/2" thick and 1" thick, instead of two sheets of 3/4 inch thick. Since both sheets will be stuck together with PB, Titebond, or whatever...will it make any difference what thickness's I use to obtain that 1-1/2"?

Also, the original deck was only 3/8" thick, I plan on using 1/2" for the deck, however the cap on this boat not only is attached along the outer area, but it also sits on the deck on the inside. Anyone think that raising the interior area a little might cause a problem?



As always, all input and replies are greatly appreciated. Thanks everyone.

 

[jigngrub]

I figured you'd feel good about removing the transom, the way they slap boats together at the factory it's a wonder they float sometimes.

Get the 15/32 plywood for the deck, you should be able to work around the 3/32 thicker than the 3/8".

 

[Woodonglass]

This will require the new transom to be approximately 1" longer (wider) that previous. My thinking is that the additional bonding to the port and starboard hull will be a good thing. I will probably go back to filling the area between the transom and rear of the hull with flotation foam. Not sure I understand the need for the additional 1" in width. From the pic I'd say you should make the transom exactly to the dimension of the center section of the hull and then use the glass to tab it to the hull on the stern and the bottom. Along with the PB glued to the hull it will be a tank.

The plywood is 1-1/2" thick, it may be a little strange, but I can save $4.00 by purchasing a sheet of 1/2" thick and 1" thick, instead of two sheets of 3/4 inch thick. Since both sheets will be stuck together with PB, Titebond, or whatever...will it make any difference what thickness's I use to obtain that 1-1/2"? Not sure where you're going to get 1" thick plywood. I've not seen it available in to many places. If you in fact can get it then there's no problem using it with the 1/2" Titebond III is and excellent glue to laminate the plywood with,

Also, the original deck was only 3/8" thick, I plan on using 1/2" for the deck, however the cap on this boat not only is attached along the outer area, but it also sits on the deck on the inside. Anyone think that raising the interior area a little might cause a problem? Since Parts of your Cap sit on top of your deck, you should be careful raising the height to much. I doubt 1/8" will be a problem.

See my responses in Red Above

 

[Daniel1947]

Thanks Jigngrub for the info and yes, you are correct. After removing the transom, I was happy I did it. To be honest it would have probably been OK after a couple layers of resin and cloth, but what the heck...I will feel better knowing that all the lumber I use is new. I have a local supplier that carries Marine grade ply, and yes I know it is a little more expensive, but there isn't any Arauco anywhere close to Memphis. So, that is what I plan to use.

Thanks to you also Wood, and you bring up an interesting point if I understand you correctly; I had also thought about just attaching it in the center - "blue square" and doing away with the additional lumber - "yellow circle. That would make the transom approximately 30" across the top, 32" along the bottom and 17" top to bottom; and leaving both sides open.



My original idea was to extend the transom the full width of the hull, attaching it along the bottom and up the sides of the port and starboard sides, and of course attaching it to the rear of the hull in the original area. This area on the rear of the hull was only approximately 30" across the top, 32" along the bottom and 17" top to bottom - "blue square" and as I stated previously, there was absolutely no attachment outside of the center area "yellow circles." Even along the bottom of the transom, the area outside of the center was not attached to the hull bottom (or at least not with anything but a few thin areas where some resin ran down. The void behind the transom was just filled with foam - "yellow circles."





I had originally figured that by extending the width of the transom so that it made contact with the sides of the hull, and attaching it there with PB and tabbing, that it would lend a lot of strength to the rear of the boat. But, what you are suggesting is if I just cut out a piece of 30" x 17" x 32" and make it 1-1/2" thick, seal it with resin and cloth, attach it to the hull will PB and tab it in properly, I can do away with the additional wood and probably save 20 to 30 lbs? Sounds like a reasonable idea Wood.

 

[Rickmerrill]

Any combo of wood that gets you to thickness is fine. I liked the TightBond III for wood on wood. You can raise the deck a little but at some point stability becomes a concern. Also the hull probably widens as you go up so just make sure that doesn't bite you.

 

[Woodonglass]

It's hard to tell from your pics but...I believe this drawing depicts how the stern of your boat is and how the transom is configured. Is this correct? If so then what I proposed Might work but you have other issues to consider such as the Tow Eyes and how they are attached etc... Can you get a pic of the stern of the boat from a Downward view so I can see what it actually looks like or does the drawing acurately depict it???