I have a 1981 Hunter 27, it has a hard liner inside the cabin. The cabin top hand rail currently has screws that hold it down. I want to change this to bolts. I beleave there is an air space between the liner and the top. Has any one else made this change? How did it go? What did you do to cover any holes in the cabin liner? I figure it might be a good idea to ask before I start drilling.
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Gord May
Good idea Richard!
You can get plastic snap-in hole plugs to finish the holes in the liner (Home Depot & others have them). Get the largest plugs available before you drill (hole saw?) the liner. You may want to use rectangular backing plates (as wide as the hole, but longer), rather than washers to get a stronger back-up. Don't forget to epoxy seal the edges of the fibreglass deck boltholes, before re-installing the rail. Good luck & Regards, Gord
You can get plastic snap-in hole plugs to finish the holes in the liner (Home Depot & others have them). Get the largest plugs available before you drill (hole saw?) the liner. You may want to use rectangular backing plates (as wide as the hole, but longer), rather than washers to get a stronger back-up. Don't forget to epoxy seal the edges of the fibreglass deck boltholes, before re-installing the rail. Good luck & Regards, Gord
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Gord May
Good idea Richard!
You can get plastic snap-in hole plugs to finish the holes in the liner (Home Depot & others have them). Get the largest plugs available before you dril (hole saw?) the liner. You may want to use rectangular backing plates (as wide as the hole, but longer), rather than washers to get a stronger back-up. Don't forget to epoxy seal the edges of the fibreglass deck boltholes, before re-installing the rail. Good luck & Regards, Gord
You can get plastic snap-in hole plugs to finish the holes in the liner (Home Depot & others have them). Get the largest plugs available before you dril (hole saw?) the liner. You may want to use rectangular backing plates (as wide as the hole, but longer), rather than washers to get a stronger back-up. Don't forget to epoxy seal the edges of the fibreglass deck boltholes, before re-installing the rail. Good luck & Regards, Gord
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Ed Schenck
Not necessary.
I had also considered bolts for my H37C. Or maybe just one on each end. I have four handrails, two are about eight feet and two are five feet. After a winter of varnishing I reinstalled(temporarily I thought) with the original screws. But before that, taking Steve's(Dion) and Gord's advice, I drilled the holes much larger and filled with an epoxy mix. Then I drilled new starter holes and screwed the rails back down. If you hooked a crane to those rails the boat would lift or the rails would break, the screws would not pull out. So do we really need to drill through the liner?
I had also considered bolts for my H37C. Or maybe just one on each end. I have four handrails, two are about eight feet and two are five feet. After a winter of varnishing I reinstalled(temporarily I thought) with the original screws. But before that, taking Steve's(Dion) and Gord's advice, I drilled the holes much larger and filled with an epoxy mix. Then I drilled new starter holes and screwed the rails back down. If you hooked a crane to those rails the boat would lift or the rails would break, the screws would not pull out. So do we really need to drill through the liner?
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Terry Arnold
cabin top handrail fastening on cherubini boats
I believe that all of the Cherubini boats are constructed pretty much alike as far as the cabin roof section and the attachment of handrails, i.e. fastened with bronze screws into a plywood insert glassed to the top layup. The inner liner is a separate section and there is airspace between them as Richard suggests of variable dimension. This airspace will certainly complicate any bolt through arrangement since to keep from deforming and perhaps cracking the lower liner in tightening up any through fasteners, there must be some kind of structural fill injected between the lower and upper sections. In reworking my H33, I overdrilled the original holes from the top and backfilled with epoxy as Ed did and agree with him that the strength from the blind wood screws imbedded in the epoxy is more than adequate. To prevent future moisture migration down the screw I left a pronounced dimple in the epoxy in backfilling the over drilled hole rather than finish out flush with the top cabin surface and likewise cut out a dimple on the bottom of the rail with a screw countersink. These two when mated together in assembly then provide an elarged more or less sphherical surface around the screw at the critical junction when the whole assembly is bedded down with caulk, hopefully guaranteeing a permanent seal. I also used the rails as a kind of template immediately after backfilling with the epoxy, drilling pilot holes into the green epoxy and then forming threads by running in and then backing out the screw to be used as permanent attachment, thus further strengthening the screw anchorage.
I believe that all of the Cherubini boats are constructed pretty much alike as far as the cabin roof section and the attachment of handrails, i.e. fastened with bronze screws into a plywood insert glassed to the top layup. The inner liner is a separate section and there is airspace between them as Richard suggests of variable dimension. This airspace will certainly complicate any bolt through arrangement since to keep from deforming and perhaps cracking the lower liner in tightening up any through fasteners, there must be some kind of structural fill injected between the lower and upper sections. In reworking my H33, I overdrilled the original holes from the top and backfilled with epoxy as Ed did and agree with him that the strength from the blind wood screws imbedded in the epoxy is more than adequate. To prevent future moisture migration down the screw I left a pronounced dimple in the epoxy in backfilling the over drilled hole rather than finish out flush with the top cabin surface and likewise cut out a dimple on the bottom of the rail with a screw countersink. These two when mated together in assembly then provide an elarged more or less sphherical surface around the screw at the critical junction when the whole assembly is bedded down with caulk, hopefully guaranteeing a permanent seal. I also used the rails as a kind of template immediately after backfilling with the epoxy, drilling pilot holes into the green epoxy and then forming threads by running in and then backing out the screw to be used as permanent attachment, thus further strengthening the screw anchorage.
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David Foster
Mine are drilled through the liner
and fastened with bolts, along with the deck hardware associated with leading lines back to the cockpit. Yes, this tightens the liner up to the inside ofe the cabin roof. No, there were no problems from this slight deformation. I covered the nuts, bolts, and washers with a cherry board on which I mounted a teak hand rail for inside the cabin. It gives great handholds for the stove, or getting back to the head under way. David Lady Lillie
and fastened with bolts, along with the deck hardware associated with leading lines back to the cockpit. Yes, this tightens the liner up to the inside ofe the cabin roof. No, there were no problems from this slight deformation. I covered the nuts, bolts, and washers with a cherry board on which I mounted a teak hand rail for inside the cabin. It gives great handholds for the stove, or getting back to the head under way. David Lady Lillie
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Gord May
Screws are not structural!
While screws may seem to be adequate fasteners - they are NOT suitable for handholds nor any other structural application. The backfilled epoxy (mentioned by Ed &Terry etc) prevents moisture from entering the fibreglass deck skins and core (if any) and provides support against compression of the core. Though better than screwing into skin & core, screwing into the epoxy (backfill plug) is TOTALLY INADEQUATE!!! BTW - I really like Terry's idea of dimpling the mounted hardware to accept the convexity left on his epoxy backfill plug. Deck hardware should be mounted on a raised pad, or a sloping surface, to prevent standing water at the (sealed) fastener holes. This is not always practical - hence Terry's idea. Thru-Bolts are nutted on the underside of the deck, above the liner, hence no compression on the liner. Access to the U/side of deck is thru' holes drilled in liner, then plugged /w plastic hole plugs/caps. These plug-caps are only about 1/2" diameter, so recommend a rectangular backing plate @ about 7/16" x 2", which will slide up through the round hole, and provide more load distribution than a small washer. Regards, Gord
While screws may seem to be adequate fasteners - they are NOT suitable for handholds nor any other structural application. The backfilled epoxy (mentioned by Ed &Terry etc) prevents moisture from entering the fibreglass deck skins and core (if any) and provides support against compression of the core. Though better than screwing into skin & core, screwing into the epoxy (backfill plug) is TOTALLY INADEQUATE!!! BTW - I really like Terry's idea of dimpling the mounted hardware to accept the convexity left on his epoxy backfill plug. Deck hardware should be mounted on a raised pad, or a sloping surface, to prevent standing water at the (sealed) fastener holes. This is not always practical - hence Terry's idea. Thru-Bolts are nutted on the underside of the deck, above the liner, hence no compression on the liner. Access to the U/side of deck is thru' holes drilled in liner, then plugged /w plastic hole plugs/caps. These plug-caps are only about 1/2" diameter, so recommend a rectangular backing plate @ about 7/16" x 2", which will slide up through the round hole, and provide more load distribution than a small washer. Regards, Gord
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Ed Schenck
Another case for screws.
David's mentioning adding inside handrails makes my case for screws. My boat has handrails the length of both sides of the salon. And right under the handrails on the cabintop. If I drilled through I would first have to remove the inside ones and figure out how to reattach. Not sure I agree with Gord's "not structural!". If the rail is going to break before the screws pull out to me that is structural. Are you suggesting that we all replace our teak handrails with stainless? If you are putting that much stress on the rails you should be wearing a harness with properly installed jacklines.
David's mentioning adding inside handrails makes my case for screws. My boat has handrails the length of both sides of the salon. And right under the handrails on the cabintop. If I drilled through I would first have to remove the inside ones and figure out how to reattach. Not sure I agree with Gord's "not structural!". If the rail is going to break before the screws pull out to me that is structural. Are you suggesting that we all replace our teak handrails with stainless? If you are putting that much stress on the rails you should be wearing a harness with properly installed jacklines.
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Gord May
The
Pull-out force is transmitted through the "structurally sound" screw (it's not, but no matter) to the epoxy back-cut plug, to the OUTER SKIN of the cored deck. Unless you back-cut the core very deeply, you have the load bearing on a very small surface of the vey thin outer FRG skin. OMO Gord
Pull-out force is transmitted through the "structurally sound" screw (it's not, but no matter) to the epoxy back-cut plug, to the OUTER SKIN of the cored deck. Unless you back-cut the core very deeply, you have the load bearing on a very small surface of the vey thin outer FRG skin. OMO Gord
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Terry Arnold
Cherubini handrail specifics
Gord, I'm going to have to agree with Ed here. The Cherubinis have had a lifespan of at least 20 years and the handrail attachment mode of wood screws through teak handrails into an underlying core of plywood works. In my boat, many of the original bronze screws came out ( I removed them all) with the original factory bright finish still there. Where there was deterioration, it was clearly the result of water intrusion. In each of the water damaged areas, the fiberglass was cracked in a more or less radial pattern around the screw hole and the hole was enlarged, indicating that the initial failure was caused by the imposition of an excessive lateral load (probably the result of an earlier owner tying off a dock line or attaching a running rigging component to the handrail. At any rate, the failure was from a lateral movement of handrail bringing along the top of the screw rather than a failure from pull out and such failure would have occured with any fastener of like diameter, whether through bolted or not. Gord's post allocating the entire adhension between the epoxy core and the boat to the outer fiberglass skin does not match my experience with epoxy. Epoxy adheres very well indeed to wood and so strength development extends from the fiberglass skin right down to the bottom of the plug which stops in the plywood or the bottom fiberglass layup encasing the plywood. Gord's idea of tightening a through bolt on the bottom of the upper layup rather than on the inner liner and then plugging the access hole through the liner, though attractive in concept, runs into problems with the Cherubini installation at least since the space between the liner and upper layup is highly variable, varying down to zero in which case there would be no room for the nut and washer and then the plug. Anybody wishing to try this out for handrails or any other through bolted installation on a Cherubini would be well advised to do some prospecting along the route of proposed bolts, to determine whether or not there is the requisite space to do what Gord suggests which certainly would result in a cleaner installation than one that ended with raw bolts, washer, and nuts showing below the liner. Bottom line for me is that the handrail is simply that, and if used for steadying in a seaway, the factory attachment will suffice.
Gord, I'm going to have to agree with Ed here. The Cherubinis have had a lifespan of at least 20 years and the handrail attachment mode of wood screws through teak handrails into an underlying core of plywood works. In my boat, many of the original bronze screws came out ( I removed them all) with the original factory bright finish still there. Where there was deterioration, it was clearly the result of water intrusion. In each of the water damaged areas, the fiberglass was cracked in a more or less radial pattern around the screw hole and the hole was enlarged, indicating that the initial failure was caused by the imposition of an excessive lateral load (probably the result of an earlier owner tying off a dock line or attaching a running rigging component to the handrail. At any rate, the failure was from a lateral movement of handrail bringing along the top of the screw rather than a failure from pull out and such failure would have occured with any fastener of like diameter, whether through bolted or not. Gord's post allocating the entire adhension between the epoxy core and the boat to the outer fiberglass skin does not match my experience with epoxy. Epoxy adheres very well indeed to wood and so strength development extends from the fiberglass skin right down to the bottom of the plug which stops in the plywood or the bottom fiberglass layup encasing the plywood. Gord's idea of tightening a through bolt on the bottom of the upper layup rather than on the inner liner and then plugging the access hole through the liner, though attractive in concept, runs into problems with the Cherubini installation at least since the space between the liner and upper layup is highly variable, varying down to zero in which case there would be no room for the nut and washer and then the plug. Anybody wishing to try this out for handrails or any other through bolted installation on a Cherubini would be well advised to do some prospecting along the route of proposed bolts, to determine whether or not there is the requisite space to do what Gord suggests which certainly would result in a cleaner installation than one that ended with raw bolts, washer, and nuts showing below the liner. Bottom line for me is that the handrail is simply that, and if used for steadying in a seaway, the factory attachment will suffice.
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Gord May
Terry Arnold is right -
For simplicity, I ignored the excellent adhesive qualities of epoxy, in my previous post. While the main force would be upon the outer skin, there would be another(peel/tension) component exerted upon the inner skin - effectively dividing the force (to some extent) on the whole cored assembly. Good point, Terry. The radial cracking (spall) may have just as well have been caused by screwing into undersized pilot holes (a common occurance) as by from a lateral force (shear). By nature, this installation error is less likely with bolted fastenings than /w screws. Once the screw-holes became enlarged and spalled, there would bot have been even a small fraction of the original holding power. A bolted and BACKED bolt, however, would not be bearing upon the entire skin-core-skin assembly, and not relying on the circumferential strength (? help me here, I'm old & forgetfull) of the aperture. Terry indicated that his removed brass screws (not as strong as silicon bronze or S/S) were "factory bright", with some of them (clearly) dammaged by water intrusion. Unless laid into uncured epoxy, every fastening is waterproofed with adhesive caulking (and by installing on raised/sloped surfaces) independant of the strucure (to which it's fastened). Screws are more likely to "work" than are locked nuts & bolts, so dammage to the sealant is more likely. Shear loads will be very hard on any linear attachment (screw, bolt, nail, etc), which requires sufficient fastener diameter. Terry is also correct in advising that the prudent installer will always check clearances (etc) prior to drilling any hole in a particular application. I cannot speak to how much space any specific boat has in any particular place. Installer beware! I disagree /w Terry's botton line - that a handrail is simply for steadying. I have several (personal) rules on the subject: (1) If it looks like (or could be used as) a handhold - IT IS. This includes things like Bimini & Dodger frames. (2) If it's a handhold (see 1 above), IT IS STRUCTURAL - and must be treated as though my life depends upon it (because it may). This requires the most secure assembly possible under the circumstances. OMO, Gord
For simplicity, I ignored the excellent adhesive qualities of epoxy, in my previous post. While the main force would be upon the outer skin, there would be another(peel/tension) component exerted upon the inner skin - effectively dividing the force (to some extent) on the whole cored assembly. Good point, Terry. The radial cracking (spall) may have just as well have been caused by screwing into undersized pilot holes (a common occurance) as by from a lateral force (shear). By nature, this installation error is less likely with bolted fastenings than /w screws. Once the screw-holes became enlarged and spalled, there would bot have been even a small fraction of the original holding power. A bolted and BACKED bolt, however, would not be bearing upon the entire skin-core-skin assembly, and not relying on the circumferential strength (? help me here, I'm old & forgetfull) of the aperture. Terry indicated that his removed brass screws (not as strong as silicon bronze or S/S) were "factory bright", with some of them (clearly) dammaged by water intrusion. Unless laid into uncured epoxy, every fastening is waterproofed with adhesive caulking (and by installing on raised/sloped surfaces) independant of the strucure (to which it's fastened). Screws are more likely to "work" than are locked nuts & bolts, so dammage to the sealant is more likely. Shear loads will be very hard on any linear attachment (screw, bolt, nail, etc), which requires sufficient fastener diameter. Terry is also correct in advising that the prudent installer will always check clearances (etc) prior to drilling any hole in a particular application. I cannot speak to how much space any specific boat has in any particular place. Installer beware! I disagree /w Terry's botton line - that a handrail is simply for steadying. I have several (personal) rules on the subject: (1) If it looks like (or could be used as) a handhold - IT IS. This includes things like Bimini & Dodger frames. (2) If it's a handhold (see 1 above), IT IS STRUCTURAL - and must be treated as though my life depends upon it (because it may). This requires the most secure assembly possible under the circumstances. OMO, Gord
Alright already!
These boats have lasted for over 25 years with screws holding the hand rails in place. While it may be well and good that through bolting would be a better way to go, how can you argue that the old system has worked. This is a similar arguement about the ports. We hear this complaint once a month about the shitty ports that were used on the Hunters. The plastic gray ports have lasted 15-20 years without any problems. Nothing lasts for ever (except for dirt)!
These boats have lasted for over 25 years with screws holding the hand rails in place. While it may be well and good that through bolting would be a better way to go, how can you argue that the old system has worked. This is a similar arguement about the ports. We hear this complaint once a month about the shitty ports that were used on the Hunters. The plastic gray ports have lasted 15-20 years without any problems. Nothing lasts for ever (except for dirt)!
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