Glue or fibreglass?- wood to inner hull

[MM5AHO]

I want to attach some timbers to the hull (inside) on which to mount a calorifier. Should I use a glue (what type?) or should I fibreglass the timbers in place?
The position is under the cockpit, accessible through the quarterberth, bit cramped for space, but I can reach there over the driveshaft.
Whatever system will require good clean surface, but is there a suitable glue to attach timber directly to the hull fibreglass?

 

[Poignard]

Best thing I've found for this job is epoxy

 

[saxonpirate]

Geoff.....As long as the area that you want to attach the grounds to is abraded and clean (wipe off with acetone) epoxy will give you an incredibly strong bond for your grounds.

Ok, you could argue that glassing in would be an all round better job, but provided the calorifier is not humongous and the grounds are wide (to give a substantial gluing area) epoxy should do the job.

It will certainly save you the job of glassing in a confined space.

 

[WoodyP]

This is copywrite to Old Salt Oz who replied to a similar message that I posted. I think it says it all.

"If this timber is going low down in the hull I would look at treating it with an epoxy first then using epoxy resin and micro fibres to glue it into position.

Method:
Cut and shape timber including any holes to be drilled. Wipe to remove any dust and apply epoxy mixed with 30% Methylated Spirits, this will thin the resun and assist penetration, apply extra on the end grain; when tacky apply 4 coats wet on tacky to avoid sanding between coats.

The area they will mounted will have to ground back to glass to get the best bond, wipe clean, mix epoxy and add micro fibres to about tooth paste consistency, apply and smooth out with the tip of a broom handle, small fish paste jar or the back of a plastic spoon to form a gusset. Clean up any excess when still wet because this stuff is very hard to sand off after setting.

Use shallow containers to mix epoxy to avoid heat build up, put 2 latex gloves on each hand, when they get sticky just pull the top one off.

After curing sand off any sharp bits and apply a paint, flow coat or mix some white pigment into your epoxy resin and paint that on. Epoxy must be protected from UV light to avoid deterioration.

Micro fibres make a very strong and hard glue, if you try pulling the timber off, the timber will break, but not the micro fibre joint.

Hope this helps.

Avagoodweekend..."

Thanks to the Antipodes. Even though you whupped us today.
George

 

[markdj]

Epoxy requires at least 15 degrees C to work, otherwise you will have a big sticky mess to clean up.

Also, trying to hold the wood in place while epoxying or fiberglassing is impossible.

My advice is to use CT1 or sikaflex to glue the wood in place and make a bead around the wood.

Next day you can either:

1. paint over the wood with bilge paint or flocoat, or...

2. chamfer, abrade and fiberglass the wood using woven roving and either fiberglass resin or epoxy but both will need 15oC to work. 3-4 layers should be plenty to give more strength and seal the wood. Finish with bilge paint or flocoat.

You do not need to go for step 2. I have glued a strip of teak direct onto gelcoat using CT1. After a day (not full strength yet) I was able to hang off the wood, my feet in the air with no movement in the piece of wood taking my full weight.

 

[William_H]

Fibre glass or Glue?

The point is glue is another name for resin used in f/g layup.
So yes you glue the wood to the hull. You can then use fibreglass (cloth) to enable the glue (resin) to be built up around and over the wood to make an even better structural joint.
So it all depends on how much strength you need. Many "glues" are actually easier to use as they are stickier so make it easier to hold the wood in place while it dries. If however you use epoxy (with a filler if you want) then you can use the same resin to saturate fibreglass to make more structurally strong fibreglass attachments. The resin in the fibretglass will chemically bond to the resin (glue) to make it all stronger.
So for super strength I would suggest the piece of wood with bolts set in place for the calorifier is glued into place. You will need some sort of prop to hold in place while epoxy goes hard. Then put in a fillet of resin with filler to a nice thick consistency around the edges so that you can then lay cloth from the hull over the wood and back to the hull on the other side.(from top to bottom and side to side) Make sure there are no air bubbles under the cloth then add more layers as you think fit.
Now this will make a super strong attachment possibly an overkill possibly just glue will be adequate.
good luck olewill

 

[oldsaltoz]

This is copywrite to Old Salt Oz who replied to a similar message that I posted. I think it says it all.

"If this timber is going low down in the hull I would look at treating it with an epoxy first then using epoxy resin and micro fibres to glue it into position.

Method:
Cut and shape timber including any holes to be drilled. Wipe to remove any dust and apply epoxy mixed with 30% Methylated Spirits, this will thin the resun and assist penetration, apply extra on the end grain; when tacky apply 4 coats wet on tacky to avoid sanding between coats.

The area they will mounted will have to ground back to glass to get the best bond, wipe clean, mix epoxy and add micro fibres to about tooth paste consistency, apply and smooth out with the tip of a broom handle, small fish paste jar or the back of a plastic spoon to form a gusset. Clean up any excess when still wet because this stuff is very hard to sand off after setting.

Use shallow containers to mix epoxy to avoid heat build up, put 2 latex gloves on each hand, when they get sticky just pull the top one off.

After curing sand off any sharp bits and apply a paint, flow coat or mix some white pigment into your epoxy resin and paint that on. Epoxy must be protected from UV light to avoid deterioration.

Micro fibres make a very strong and hard glue, if you try pulling the timber off, the timber will break, but not the micro fibre joint.

Hope this helps.

Avagoodweekend..."

Thanks to the Antipodes. Even though you whupped us today.
George

Great game though.

Avagoodweekend......

 

[TQA]

The point is glue is another name for resin used in f/g layup.
So yes you glue the wood to the hull. You can then use fibreglass (cloth) to enable the glue (resin) to be built up around and over the wood to make an even better structural joint.
So it all depends on how much strength you need. Many "glues" are actually easier to use as they are stickier so make it easier to hold the wood in place while it dries. If however you use epoxy (with a filler if you want) then you can use the same resin to saturate fibreglass to make more structurally strong fibreglass attachments. The resin in the fibretglass will chemically bond to the resin (glue) to make it all stronger.
So for super strength I would suggest the piece of wood with bolts set in place for the calorifier is glued into place. You will need some sort of prop to hold in place while epoxy goes hard. Then put in a fillet of resin with filler to a nice thick consistency around the edges so that you can then lay cloth from the hull over the wood and back to the hull on the other side.(from top to bottom and side to side) Make sure there are no air bubbles under the cloth then add more layers as you think fit.
Now this will make a super strong attachment possibly an overkill possibly just glue will be adequate.
good luck olewill

Err as a bit of a glue anorak the above makes me itchy. Yeah I know to much glass splinters.

The resin used in f/g layup is very rarely epoxy, It is usually a totally different resin an unsaturated polyester or vinylester an epoxy based intermediate with a high styrene content.

You need to know what your hull is made from. epoxy will stick well to epoxy, polyester or vinylester.

Polyester will stick fairly well to polyester but not as well as epoxy. Polyester does not stick well to epoxy or vinylester.

For any of the above you want a thixotropic resin as the standard stuff is too runny.
I like Wests Six10 see http://www.westsystem.com/ss/six10-introduction/

I use the word stick with caution as a discusiion of how a bond is made involves all sorts of technical / chemical anorak stuff.

There are some "glues" you could use. 5200 will "glue" timber to any of the above 3 and when fully cured the strength is excellent.

I have also had success with Gorilla glue and had good bond strength.

A usefull glue to "tack" timber in place while your other glue cures is thick superglue used with a spray kicker. Any decent model shop will have both. Get the thickest they have. Do not be tempted to use it as a primary glue for any long term use wood/glass use as it is brittle,

Belt and braces - add some glasscloth tabbing to the timber battens after fixing them in place.

 

[oldsaltoz]

Err as a bit of a glue anorak the above makes me itchy. Yeah I know to much glass splinters.

The resin used in f/g layup is very rarely epoxy, It is usually a totally different resin an unsaturated polyester or vinylester an epoxy based intermediate with a high styrene content.

You need to know what your hull is made from. epoxy will stick well to epoxy, polyester or vinylester.

Polyester will stick fairly well to polyester but not as well as epoxy. Polyester does not stick well to epoxy or vinylester.

For any of the above you want a thixotropic resin as the standard stuff is too runny.
I like Wests Six10 see http://www.westsystem.com/ss/six10-introduction/

I use the word stick with caution as a discusiion of how a bond is made involves all sorts of technical / chemical anorak stuff.

There are some "glues" you could use. 5200 will "glue" timber to any of the above 3 and when fully cured the strength is excellent.

I have also had success with Gorilla glue and had good bond strength.

A usefull glue to "tack" timber in place while your other glue cures is thick superglue used with a spray kicker. Any decent model shop will have both. Get the thickest they have. Do not be tempted to use it as a primary glue for any long term use wood/glass use as it is brittle,

Belt and braces - add some glasscloth tabbing to the timber battens after fixing them in place.

I used to use a material referred to as Gorilla hair, is this the same stuff you are referring to?

I now use Micro-fibres instead because a number of test structures tested to destruction indicated a much better bond.

When bonding I use a good quality tape or wedges rather than 'other glues' as you can suffer from chemical reactions, as well as leaving entry points for moisture contamination after curing.

I avoid the use of Thixotropic resins as by nature is has little if any penetration quality.

Avagoodweekend......

.

 

[Ubergeekian]

Whatever system will require good clean surface, but is there a suitable glue to attach timber directly to the hull fibreglass?

The big potential problem I can see is that glue is pretty weak stuff if used to fill big gaps. If you can get a close fit between the wood and the hull then as others have said an epoxy would seem to be the answer - a good thick one, that is, like an industrial Araldite, and not a runny layup one.

If the gaps are going to be big (more than a millimetre or two) then I'd probably bed the bearers down on an epoxy putty and then either glass over them or glass fillet both sides, depending on how high the wood was.

I am just about to do something fairly similar: restoring quarter berths to a Hunter 490 for which I need to add various bits of woodwork to the hull.

 

[snowleopard]

Fibreglass will work - for a while - but eventually the bond will fail.

Polyester to polyester makes a good bond (some will tell you different but as long as you abrade properly it works just fine). Polyester to wood is unreliable so for that job epoxy is the way to go.

Here is an alternative: instead of using timber, make it from solid GRP.

First make a flat piece of GRP by laying up 4 or more layers of glass fibre onto a smooth board - I use an offcut of kitchen worktop or contiboard shelf treated with a bit of wax polish so it releases easily.

Shape that and hold it in place with e.g. masking tape and glass it to the hull with a strip of mat and resin. Once it has set, apply further strips both sides and you will have a solid job with no risk of rot or delmination. Just be sure to abrade any surface before applying wet resin or it won't stick.

Remember that a full calorifier is pretty heavy so you need a strong bond, you wouldn't want it breaking loose at sea!

 

[TQA]

I used to use a material referred to as Gorilla hair, is this the same stuff you are referring to?


I avoid the use of Thixotropic resins as by nature is has little if any penetration quality.

Avagoodweekend......

.

Gorilla Glue is this stuff http://www.gorillaglue.com/glues/gorillaglue/index.aspx se the original vesion for wood to fibreglass. Good stuff as it expands as it cures and is suitable for outdoor use.

I agree that a thixotropic glue has little penetration. Easy fix; paint on a little laminating epoxy resin on both surfaces, wait till it kicks then apply the goopy stuff.

 

[rtchina]

To hold in place whist curing, I would leave a couple of spots expoxy free and use hot melt glue to hold whilst setting. I have used this to hold ceramic fittings in place whilst the "glue" in this case silicon, sets. Will even work on vertical surfaces.

 

[oldsaltoz]

Gorilla Glue is this stuff http://www.gorillaglue.com/glues/gorillaglue/index.aspx se the original vesion for wood to fibreglass. Good stuff as it expands as it cures and is suitable for outdoor use.

I agree that a thixotropic glue has little penetration. Easy fix; paint on a little laminating epoxy resin on both surfaces, wait till it kicks then apply the goopy stuff.

Not the same glue, the original Gorilla Hair was much like micro-fibres and mixed with resin to make a very strong glue.

Think I'll stick with just one pot of resin and not contaminate other tools, Mix a small batch of resin add Micro fibres to get the desired thickness, smooth out, lay first cloth and add more resin etc etc.

Avagoodweekend......

 

[MM5AHO]

Thanks for the replies. The calorifier is small (22litre) and surface to be attached to relatively flat, so an adhesive system might work well.
Some terms are hard to be specific about. For example "epoxy". On its own, without specifying the product leaves me wondering just what was meant. Epoxy is more a family of chemicals rather than a product.
But I have some good leads here of products to try.
Temperature might be my problem. Winter maintenance in Scotland is often conducted under 5deg C, so some heating might be appropriate.
Geoff

 

[oldsaltoz]

Thanks for the replies. The calorifier is small (22litre) and surface to be attached to relatively flat, so an adhesive system might work well.
Some terms are hard to be specific about. For example "epoxy". On its own, without specifying the product leaves me wondering just what was meant. Epoxy is more a family of chemicals rather than a product.
But I have some good leads here of products to try.
Temperature might be my problem. Winter maintenance in Scotland is often conducted under 5deg C, so some heating might be appropriate.
Geoff

The term 'Epoxy' refers to the type of resin as opposed to more standard poly resins. Standard resins do not stick well to timber, howerver epoxy resin does.

I would expect the total weight of the water heating system would be close to 25 Kg when static. Consider how movement may effect this weight and the dynamics or a fluid filled vessel. It will have to be a strong base to prevent movement so some fixing to the base or a suitable nearby bulkhead.

Avagoodweekend......

 

[Ubergeekian]

Thanks for the replies. The calorifier is small (22litre) and surface to be attached to relatively flat, so an adhesive system might work well.
Some terms are hard to be specific about. For example "epoxy". On its own, without specifying the product leaves me wondering just what was meant. Epoxy is more a family of chemicals rather than a product.
But I have some good leads here of products to try.

Indeed. I used to stick to Ciba's industrial range (5000 series, I think it was) which let you choose the properties you needed: there were variations in viscosity, setting speed, tensile strength, shear strength and compatibility with other resins. It's been a while, though, and I donlt think Ciba is in the epoxy business these days. I used to get it from Scott Bader, who can probably advise on modern alternatives.

 

[saxonpirate]

Geoff.... I work in yacht construction and repair, and always use SP Systems Products and have done for many years. The above photo shows a handy pack which is ideal for small jobs. This epoxy is SP 106. With this you'll need a 0.5kg pot of Microfibers (for thickening), a couple of measured mixing pots, a pack of tongue depressors (like large lollipop sticks) and some acetone for cleaning.

Temperature : Min 15% C so if you have shore-power, a heater is necessary.
SP 106 is a multi-purpose epoxy....all the information you need, including hints on using epoxy in cold weather, is available in PDF format at the URL below.

http://www.gurit.com/sector_introduction.asp?section=0001000100220054&pdftestB

My supplier in Cornwall for these products is Seaware....see URL below

http://www.seaware.co.uk/Default.aspx

They are very helpful and I'm sure will advise on your product requirements. The web site will give you a good idea of what is available and prices anyway. Look under Resins in the index.

 

[Pete7]

Remember that a full calorifier is pretty heavy so you need a strong bond, you wouldn't want it breaking loose at sea!

Just incase SL's comment is over looked I would to draw your attention to it again. I would be using epoxy resin rather than glue, even if it meant waiting until next spring.

Pete

 

[Clyde_Wanderer]

This is copywrite to Old Salt Oz who replied to a similar message that I posted. I think it says it all.

"If this timber is going low down in the hull I would look at treating it with an epoxy first then using epoxy resin and micro fibres to glue it into position.

Method:
Cut and shape timber including any holes to be drilled. Wipe to remove any dust and apply epoxy mixed with 30% Methylated Spirits, this will thin the resun and assist penetration, apply extra on the end grain; when tacky apply 4 coats wet on tacky to avoid sanding between coats.

The area they will mounted will have to ground back to glass to get the best bond, wipe clean, mix epoxy and add micro fibres to about tooth paste consistency, apply and smooth out with the tip of a broom handle, small fish paste jar or the back of a plastic spoon to form a gusset. Clean up any excess when still wet because this stuff is very hard to sand off after setting.

Use shallow containers to mix epoxy to avoid heat build up, put 2 latex gloves on each hand, when they get sticky just pull the top one off.

After curing sand off any sharp bits and apply a paint, flow coat or mix some white pigment into your epoxy resin and paint that on. Epoxy must be protected from UV light to avoid deterioration.

Micro fibres make a very strong and hard glue, if you try pulling the timber off, the timber will break, but not the micro fibre joint.

Hope this helps.

Avagoodweekend..."

Thanks to the Antipodes. Even though you whupped us today.
George

OSO definatly knows what he is talking about, and that is the way I would do it, but after the stage of priming the wood with diluted epoxy I would aim to get it bonded in place while the later epoxy is still tacky to save the neccessity for sanding it if it is cured and to give a stronger bond.
C_W