1992 Astro Restoration

[1fishbone]

Re: 1992 Astro Restoration

Go that way...the way you've seen.

I know I was 'told' by an old Norwegian shipwright I worked for, he would want a bedding, usually cardboard, in deck supports, upper deck not the deck you walk on, control box braces etc. The glass work would contract and leave an indentation, on the opposite side, which needed to filled and fared.

He never wanted this on a stringer.

Also, go with 3/4" stringers, keep them all the same...less work/materials, better than original!

 

[1fishbone]

Re: 1992 Astro Restoration

Here is another good example 'hard spots' from drewpster:

The fillets are meant to serve as a smooth transition for the covering fiberglass to lay in to. Fillets are used in inside corners because the cloth will tend to lift out of a sharp inside corners leaving voids when it hardens. This gives water a place to collect. I made my filleting compound from resin, cabosil (thickener), talc (thickener) and chopped fibers. The chopped fibers serve to add a little strength to the fillet itself to prevent the compound from fracturing over time. Resin and thickener alone will fracture leaving tiny voids. Again, a place for water to collect. Fillets add very little structural strength and they will flex. They are generally small and simply round out the inside corner. Therefore they do not create a hard spot.

Fillets alone will not provide a good bond between the bulkhead and the skin of the hull. You need to either glass in strips down the inside corners (tabbing) of the bulkhead or cover it completely down the sides and on to the hull skin. Or you can do both. I prefer both. I either case the extra step of making fillets prior to glassing will help the cloth lay in to the

In LARGE commercial boats, for engine support stringers, we did exactly the same thing, put down a bed of chop, resin and chopped glass, then set stringers in before it cured...a perfect fit to the hull and a gradual transition...no sharp edge which may leave a void.
The stringer was cut from a template and fit the hull very closely.

This extreme for our little pleasure boats, but as with all fiber-glassing, keep in mind the voids we can't get the glass to form.

 

[Cadwelder]

Re: 1992 Astro Restoration

Advice taken, I'm going to build the stringer system on the bench, build a support for it and susupend it in the boat about a 1/8" - 1/4" above the hull. Tab it in good, remove the supports and then glass it all in as originally done. I'm taking 1fish and YD's advice and going with all 3/4" plywood for all the stringers. (using all marine grade plywood, cause it's the best......???)

 

[Cadwelder]

Re: 1992 Astro Restoration

Now that the stringers are solved, what is everyones thoughts about adding a flat bottom to the under deck ski locker? Originaly it was just the bare hull with carpet shaped to it, but I'm thinking of a flat bottom out of some 1/2" ply, this will make a neat storage locker and allow any water to drain back without soaking the carpet. Anyone done this?

 

[Yacht Dr.]

Re: 1992 Astro Restoration

Leave it bare hull and ditch the carpet.

Brush on some Gel or Bilgekote

YD.

 

[Cadwelder]

Re: 1992 Astro Restoration

Just as a word of advice to anyone purchasing a boat, look at the pictures in this thread and you'll see how rotten the deck and stringers are. The add on Craigslist read "A small soft spot in the floor, easy fix". I knew what I was going to find so it didn't matter to me, but it's RARE that there is ONLY a small soft spot that isn't a major repair.

 

[Cadwelder]

Re: 1992 Astro Restoration

I'm ready to install the transom back in, does a layer of .75 oz mat between the hull skin and the wood and two layers of 1708 on the inside to tie in to the hull sound ok? I used .75 oz mat between the two layers of wood already.

 

[ondarvr]

Re: 1992 Astro Restoration

What ever you use between the hull and new plywood needs to be able to fill all of the possible gaps, so unless the transom surface is very uniform a single layer of .75 oz mat won't do it. A couple of layers of 1.5 oz mat, putty, or other adhesive should be used to ensure there are no voids between the two.

 

[Cadwelder]

Re: 1992 Astro Restoration

Thanks, and yes the old transom wood was so bad it mostly fell out leaving a very smooth skin, only took some light sanding to prep it, but will heed your advice and go with a 1.5 oz Matt just to be sure. Is the 1708 okay for the inside, I have plenty of it.

 

[ondarvr]

Re: 1992 Astro Restoration

Yes, it will work well.

 

[Yacht Dr.]

Re: 1992 Astro Restoration

I think 1 layer of 1.5 oz transply to transom bond is not enough..

2 layers if not 3 would make me feel better..

1 - 1.5 oz and 2 layers of 1708 overall .. with an extra 1708 8" of tabbing for the inside would make me feel warm and fuzzy inside .

YD.

 

[Cadwelder]

Re: 1992 Astro Restoration

YD,
Are you saying 3 layers of matt between the skin(actual transom hull) and the wood??? I agree 100% with the rest as far as tabbing (I'll mostly likely carry in past 8" to more like 12" or so there) into the hull for the strength.

 

[Yacht Dr.]

Re: 1992 Astro Restoration

YD,
Are you saying 3 layers of matt between the skin(actual transom hull) and the wood??? I agree 100% with the rest as far as tabbing (I'll mostly likely carry in past 8" to more like 12" or so there) into the hull for the strength.

I was thinking 2 to 3 layers between the skin and the wood ( depending on how flat and smooth it is )

Also..make sure your skin is more then just "scuffed" .. I mean like use 36-24 grit

Happy Glassing..

YD.

 

[Cadwelder]

Re: 1992 Astro Restoration

Here are a few pictures of the progress. All the rotten wood is removed and time for the dreaded grinding. Already ground the transom skin and it cleaned up very well.

 

[Yacht Dr.]

Re: 1992 Astro Restoration

Cadwelder.. just a tid bit here..

Never leave your sanding pad face down like in pic one.. It will distort it if its a foam pad ( grinding disks are ok to do that to..not Pads ) .

Just a good habit to get into .. never lean or rest the pad on anything.

YD.

 

[Cadwelder]

Re: 1992 Astro Restoration

I was thinking 2 to 3 layers between the skin and the wood ( depending on how flat and smooth it is )

Also..make sure your skin is more then just "scuffed" .. I mean like use 36-24 grit

Happy Glassing..

YD.

I am using 36 grit, so I'm good there. I'll be clamping the wood to the transom skin to be sure it pulls up good against the wood, but I'll go with two layers to be sure. Also the wood (marine grade 3/4") is extremely flat. The two layers were laminated in a press, with a layer of 1.5 oz mat in between and wet our really well. (a freind of mine has a large press just for that purpose in a furniture shop) The transom is only 16-1/2" x 29" so it was really easy to work with.

Thanks for the advice on the pad, I normally use this grinder with metal grinding disc so I've gotten into a bad habit I guess, I'll correct that.

 

[Cadwelder]

Re: 1992 Astro Restoration

Now lets talk about the strakes, the boat has four of them that only run about 6 feet up the hull. They are currently hollow, but no doubt the wood has long since rotted away. There is only one layer of glass over them, should I cut them out and replace the wood (looks to be a 1-1/2" dowel sawed in half and laid down) or just scuff them up good and and add a layer of 1708 over them. I know a lot of manufactuers use foam cores for this, so would leaving them hollow hurt anything.

 

[Yacht Dr.]

Re: 1992 Astro Restoration

As far as your strakes go..

As long as there is enough glass in there I see no problem leaving them hollow.

Most of the time ( that I have seen ) they are filled for ease of layups on the hull..

YD.

 

[Cadwelder]

Re: 1992 Astro Restoration

I know you said it would be fine to leave them hollow but one of them is cracked badly (stepped on during grinding) they will be hard to glass over and hold the rounded shape. What around ripping a piece of 1-1/2" Schedule 20 (it's very thin) PVC conduit and using it as a form and just replacing the strakes completly. I guess my concern is just how important are they? Am I using the proper term, they are called strakes correct?

Like I said early there is only one layer of glass forming them and just my wieght cracks them.

 

[Yacht Dr.]

Re: 1992 Astro Restoration

Sorry about the late reply..

Yea..I dont know exactly what those are..but I dont think replacing with PVC is a good Idea.

Do those cracks/holes go through the bottom ? Or are they like mini-stringer things ?

Cardboard tubes cut in half would be better then PVC. Could you just put a few layers of 1708 over them to make them stronger ?

YD.

PS. You do know its ok to post a reply like " here is another pic " to Bump .