1969 Boston Whaler hull peel

[ShawtownUSA]

Hello everyone! I have a 1969 Boston Whaler Nauset (classic 16'7" hull) that had the typical deep gelcoat crazing. I have ground off all the gelcoat down to the green glass and repaired about 7 areas that had deep gouges into the hull or where the roving-woven matt was showing through the CSM. The glass in many places feels solid but in some areas I am able to take the butt of a screwdriver and push some weight into the hull and I get some slight flex. I am worried that if I go straight to fairing and painting that eventually I'll have spider cracks that show up in the paint. I have been advised from other Whaler owners to do as little as coat the whole boat in epoxy to seal the old hull, fair and then paint. Others have recommended 1-2 layers of 6 oz glass matt with epoxy and then to fair/paint. Others, including a fiberglass supplier, have recommended a layer of 1708 before fairing/painting. I'm here looking for your advice on how best to tackle the job of firming up the slight flex in the hull before starting the topcoat process. I’ve attached pictures of the hull, an example of an area that has since been repaired and some up close pictures of the hull after gel coat was removed.

I should say that I intend to use epoxy fairing compound, Interlux PrimeKote primer and Interlux Perfection paint by roll and tip.

Any suggestions would be greatly appreciated!

 

[airshot]

This is why I prefer aluminum hulls....no offense intended here, I just hate fiberglass work. Hope you get it figured out and when finnished, get us some pics, nothing cooler than a whaler runnin across the water !!

 

[ShawtownUSA]

This is why I prefer aluminum hulls....no offense intended here, I just hate fiberglass work. Hope you get it figured out and when finnished, get us some pics, nothing cooler than a whaler runnin across the water !!

I love a good aluminum boat too but there is something therapeutic about working with fiberglass. I've always loved it! I've done a lot of fiberglass repairs before but nothing quite this extensive. I'll keep folks updated as I progress!

 

[Scott Danforth]

your 55 year old whaler made it 40 years past when it was designed to last.

if you have any moisture in the foam core I would scrap it. you cant dry them out.

if you grind fiberglass, you must replace the fiberglass. pic #2 says you are almost thru to the foam.

 

[ShawtownUSA]

your 55 year old whaler made it 40 years past when it was designed to last.

if you have any moisture in the foam core I would scrap it. you cant dry them out.

if you grind fiberglass, you must replace the fiberglass. pic #2 says you are almost thru to the foam.

I did grind though the glass in areas with damage and the foam was bone dry! My question is what glass would be best to replace on the exterior hull.

 

[Scott Danforth]

I did grind though the glass in areas with damage and the foam was bone dry! My question is what glass would be best to replace on the exterior hull.

how far did you have to grind. if you just ground thru the gel, then a coat of 1.5 oz CSM would be fine prior to sanding and re-gel or paint.

if you ground a few layers deep, build back up with 1708

 

[ShawtownUSA]

how far did you have to grind. if you just ground thru the gel, then a coat of 1.5 oz CSM would be fine prior to sanding and re-gel or paint.

if you ground a few layers deep, build back up with 1708

Scott, In most places I barely ground past the gelcoat and into the primer or whatever the black layer was between the gelcoat and original glass. After I got the gelcoat off I used a finish sander to slowly take more of the black layer off until the crazed layer was gone or I got to green glass. There were a few areas where the wood support for the inside deck was where you can see (in the posted photo) seemed to go from a very thin amount of CSM to woven roving. In these areas I ground down to foam/wood, both of which were dry, and then repaired with epoxy and CSM. I'd like to add some material to the hull to strengthen it and reduce flex so that all my work on the topcoat will pay off for years to come and not spider crack/craze like the old gelcoat did. I've been advised that cloth would be better than CSM for this but there are a number of folks that recommended just CSM and epoxy. What camp are you in?

 

[Scott Danforth]

Scott, In most places I barely ground past the gelcoat and into the primer or whatever the black layer was between the gelcoat and original glass

There should not be a black layer. Just gel and fiberglass over foam. Black usually indicates some sore of bacterial or mold issue

CSM can not be used with epoxy, neither can 1708.

CSM requires the styrene to break down the binders

Using epoxy requires cloth and 1700

And you can not gel coat over epoxy

 

[kcassells]

csm has no strength value. Just go up a notch.

 

[ShawtownUSA]

There should not be a black layer. Just gel and fiberglass over foam. Black usually indicates some sore of bacterial or mold issue

CSM can not be used with epoxy, neither can 1708.

CSM requires the styrene to break down the binders

Using epoxy requires cloth and 1700

And you can not gel coat over epoxy

Planning to paint so nonissue with gelcoat and epoxy.

There definitely is a black layer under the gelcoat, uniform in thickness and with crazing through it as well.

There’s a number of manufacturers that make 1708 and 1208 that is fully stitched and comparable with epoxy, I’m just not sure I need that much bulk or weight.

 

[ShawtownUSA]

csm has no strength value. Just go up a notch.

Would that be something like 1-2 layers of 6oz cloth or up more to something like 1208?

 

[Scott Danforth]

The 08 is CSM stitched.

I would use poly over epoxy because epoxy isn't worth the extra cost.

 

[mickyryan]

when i did one this was exactly what happened to keep weight down i went with one layer of 1708 on bottom and on the inside of boat andf that was it also drill about a hole in transon every foot and stand boat up for a few days you will get most of the water out of it thats in the foam , weigh it before and after if possible then seal up holes and anywhere else water can penetrate at that age i bet shes waterlogged