Contoured ProBalsa Plus is a coated, contourable, endgrain Balsa Wood for use in marine and boatbuilding applications. Coated with a thin resin film to enhance bond with epoxy, VE and polyester resin systems. 10 lb. per cubic ft. typical density. Standard core for many OEM boatbuilders. Typical applications include hull and deck core replacement, construction of small parts and inexpensive straight core replacement. Purchase by individual sheets / boards or by the case.
Sold in 2'x4' sheets
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DIMENSIONS: 3/8" X 2' X 4'
1/2" X 2' X 4'
3/4" X 2' X 4'
Is Balsa wood a good flotation material ?
The Balsa wood I purchase was not used for floating. It was used for it's light weight. I'm repairing a Balsa Core Hull.
Then this is the material you need. It's kinda expensive but this site had the lowest price. Balsa is a good floating material. But the way it's used in a Balsa core hull it doesn't make a difference.
That is what I am trying to do with my fifteen foot bass boat.I got the top skin off...revealed what was left of the balsa core...down to the "mesh"...
what is the size 4 feet by 2 feet?
I'm not sure if you're asking thickness or size. The size is as stated, it's a sheet 4 feet long and 2 feet wide. The balsa is the same thickness as regular 3/4 inch plywood or in other words, not quite 3/4 of an inch.
It is the area of the rolled out sheet of balsa, glued to a mesh. The thickness of the balsa is 3/4 inch, 1/2 inch, or 3/8 inch, depending on which you choose.
yes-- 2x4. Comes rolled, so there is no excess size charge, although sometimes they need reminding.
what is the weigh psf?
10 pounds per cubic foot or 2.5pounds for a 3/8" thick sheet, 3.33 pounds for a 1/2" thick sheet and 5 pounds for a 3/4" thick sheet.
I am considering building a drift boat .. I am familiar with end grain balsa construction (such as J24 hulls) and thought it or even similar material that does not retain water, would be a great choice for the floor / bottom of the boat ... any thoughts / recommendations??best regards .. Stephen myles
I used it for a cockpit floor. My cockpit floor is not the hull like you are planning. I would think you could use it as a flat hull bottom, but only after applying many layrrs of fiberglass, or other composite fabric. I put like over three layers of fiberglass on both sides of the end grain. This worked very well for my sailboats cockpit floor. Go see Bateau sailboats and their web site for they engineer their boats construction. They have aforum their where you can submit boat constructionquestions
i personally wouldn't use balsa under the waterline anywhere on a boat but if the proper steps are taken to make sure it will never get touched by water then it is ok. I like to use the divinycell as a core material because it wont accept water and you can get it in large non scored sheets that still bend pretty well
The end grain balsa will retain water if soaked. If you are using it as a floor, you must waterproof it with your fiberglas.
Sir;I am replacing wet core in the cockpit of my Cape Dory 25d. I think the existing core is 3/8" and i have 3/8" replacement balsa core from Jamestown. My question is, do i need to use fiberglass cloth or mat to bond the new core to the bottom skin and if so, how can i match the existing cockpit level?
Build up with glass and epoxy then finish with textured gelcoat or paint epoxy with Kiwi Grip.
Hi Gregory, this is frank.Hey, i was planning to use the old top skin, so that is why i wanted to make sure i didnt have too much thickness. I am planning to use 17oz biaxial cloth to laminate the old skin back to acheive some joint strength? do i need to use addl. fiberglass when installing the new core?
I would definitely use glass mat over the balsa core then build it up to match the existing level. The trick is to bevel around the cut a few inches so you have room for the glass to adhere to the old base. Once its cured sand it flush and paint it.
Hello,When I did my core replacement, I just used epoxy thickened with cabosil to bond it to the bottom skin (make sure the skin is clean, and wet it out with clear epoxy first). The balsa did stick out a little at the top, but that was easy to overcome by sanding it down with an orbital sander. You may not even need to do that step if you smooth the bottom skin out and have a clean hole for the balsa to sit in. After that step, I layered glass on the top and faired with epoxy mixed with fairing filler. Hope that helps.
If the bottom skin is in good condition you should be able to use slightly thickened epoxy resin (to fill gaps) between the bottom skin and the new core material. You can weigh down the core with bags of sand until the epoxy kicks (or use vacuum bagging if very ambitious). I recommend getting the West System book "Fiberglass Boat Repair & Maintenance" which has a short chapter on repairing core related damage. Cheers, Dave
Thanks john, I am struggling with cutting the skin in the cockpit vs trying to dig out the wet balsa and inject epoxy? Area is about 8" by12"
HELLO From the dscription of your repair I think the 3/8 inch balsa core should work good. Make sure the bottom skin is clean and smooth and then just put a thin layer of epoxy on the bottom skin to bond the balsa core to the bottom skin. Then put a thin layer of epoxy on the top of the balsa core to bond the piece of the exterior fiberglass cockpit floor that you cut out to get to the wet core.My repair was a bit more challenging. I have a 1965 Pearson Commander. The core in the top of the cabin was wet and ahd to be removed. I did not want to alter the exterior of the cabin top so I did the repair from inside the cabin by working overhead. It came out fine. John H. Smith
How contour-able is this core? For instance, I've dug out the rotted balsa in my flybridge, which the floor has a slight arch to it.. How well will this contour the shape?
In this case it will be fine. Sometimes it depends on which side you put the mesh backing. It will controur in one direction easily in two directions it makes a difference. You should be fine. Resin the arear first then lay the core down then saturate. In some cases in the corners and edges I use resin with short stran clippings mixed in to radius the corners. Makes it super strong. On the top of the core lay three layers of matt and glass for the best strength.
This product fits contours easily. As long as there are no really sharp contours, in which case it will still roll over the contour, but will create gaps at the top. It's still isn't an issue as epoxy would fill the gaps when you glass over it. .
It comes in little cubes glued to a mat. This allows a lot of ability to conture to a shape. If you place the mat up you get almost unlimited flexability. Less mat down. It takes a lot of epoxy to fill the spaces in between the cubes unless it is flat. Hope that helps.
We used the Balsa core product for re-coring areas of my sons j 24 deckit worked very well no issues following or aligning with the deck contour
I have a 1987 Carver Santego 2767 that I am restoring. The 1 cockpit deck lid is rotted and I need to replace it. Would the com-29306 3/4 inch provide the support I would need (after covering with fiberglass) to hold the weight of people?
Use balsa it's great with 1708 biaxial mat. It will be strong and light
Yes, I only used 1\2 inch on my fore deck project because that is what the oem used. the strength comes from th lamination of glass and core, with the glass on both side of the core making a stress panel which resists compresion and tension, sorry for the technical answer. as long as your span is not too much it will hold people. If it is a big span glass doug fir 1x2 or 2x2 stringers into the lid across the span 18" or 20" apart and fill in the rest with the core material to make you deck lid. hope this helps.
If the core was balsa and you use the same thickness, yes it would work fine. If it was a foam core, and I'm assuming it is not if it is rotten, then the question is more difficult because foam comes in many densities.For what you are doing, I think the important thing is not so much the core, but the glass you will use. You should match the layup to the original. You most likely don't have that information. If you can measure the thickness of the original skin, this will give you an idea how many layers of glass. You need to get hold of some 1808 or 2408 fiberglass material. This is a glass/mat combi that makes laying up easy and fast. It is often not easy to find this, most marine stores sell a lightweight cloth, without mat, and this is not what you want to use. You should also taper the old skin back by grinding. Then lay up into the taper and sand to finish. One thing you can do is to make a practice layup. Take a bit of balsa core and layup several layer of glass. Let it cure, then sand and dress one edge so you can measure how thick the skin is for the number of layers you laid up. From that you can figure out how much glass and mat to use to match the old skin thickness. If you use power tools, use carbide when working with glass.The hard part of fiber glassing is getting the right materials, many of which are not available to non commercial users. Also, use epoxy. It is much easier to work with. It bonds much better in secondary bonds than does the cheaper polyester resin. Lastly, never screw into the core of any layup. You should drill out the core and replace with thicken epoxy, and then put fastener into that. This way you won't get water into the core.
MichaelThe support really comes from the glass laminent on the outside and inside not the balsa core. For what you are concerned about even a 1/2" core would probably be sufficient. I personall would make sure the laminent on each side is at least 1/8" thick. I suspect that if you look closely at the edges in other deck penatrations you will see the outside and inside laminents are about an 1/8" thick. You are talking a bending application and there the highest stress is on the inside and outside surfaces.
If your have to the balsa will suppport the wight up to around 160 to 200 lbs per sq foot is my experience on half inch balsa end grain. Much higher on the weight and the fiberglass will start to delaminate I have found. You really need to forget the balsa and go for either a new hatch, or the foam that replaces the balsa. I did my cockpit sole in the half inch end grain balsa. It worked all right put it agains is susceptable to moisture intrusion and the job will have to be done again. I will next time go for the new foams that can go where the end grain balsa is and moisture problems practically disapppear with these new foams. James Town has the foam also. Forget the end grain balsa is my recommendation. You are putting the labor in once with the foam, and maybe a couple more times with the end grain if you plan on owning the boat for many years.
Michael,I replaced a sextion of the deck on my C&C 38 with 3/8" balsa. Saturating it with resin and using fiberglass cloth top and bottom for the shell will make a strong repair.George
Hello Michael, I replaced the entire core of my 1976 Oday 27 using 3/8" ProBalsa. I then covered with 2 layers of 1208 biaxial at +/- 45 and 2 layers of 1808 biaxial at 0/90. Don't fall, a broken leg is guaranteed. The ProBalsa is easy to work with and provides a light and durable core material. Best part is it is one of the least expensive core materials. It accepts epoxy well which eliminates some of the more exotic bonding techniques such as vacuum bagging. Good luck with your project.
Thanks for all the input. It's greatly appreciated!!
The balsa would be fine for what you are doing but you would need lots of fiberglass to get it rigid. The best way would be to get some 1/8 plywood and make a sandwich laminate. Ply/core/ply the thin glass on top. Don't let balsa get wet!
i have a 20 ft pro-line open cc boat needs a new deck . what material do you suggest? money is important. thanks, bob hodges
Bob, Without a doubt Balsa coring is the way to go. I hobby restore 1960's Pearson sailboats and the only failure I have found with balsa is when holes are drilled through the deck and the holes are NOT sealed properly. Which is no fault of the Balsa. Balsa is the most economical choice for repairs and just as strong as the more expensive alternatives.
You should use the same material and thickness that is already there. Assuming it is balsa and you will be removing the top layer of the deck to get to the core using the same thickness will allow you to reuse the "panels" that you cut up. This will need to be painted or covered with some type of tread material.
Bob,I used Pro Balsa to repair/replace wet deck balsa on a S2 7.9 sailboat. I had to use the balsa to keep the boat class legal. But I would rethink using on a redecking for your power boat. I would use a non absorbing material. There are several choices out there, but in the end for a power boat over time the balsa would get wet. If you would like you can call me at 941-286-0722 to discuss.Martin Holland
Bob, Not sure this will help with your problem. I did a repair on my balsa cored sail boat deck in a 2ft sq area. I cut the top fiberglass carefully, removed the old core, cleaned the area down to the interior fiberglass, wet the area with resin, layed in 3/8 " probalsa, wet the probalsa top with resin, layed in several layers of fiberglass, primed the glass, coated with gelcoat, sanded smooth and flush. painted with Kiwi Grip non skid. Came out strong and good looking.George
I'm trying to stiffen up the cabin top on our 1983 rawson 30 ft sailboat. The cabin top flexes under foot. It is not cored, Its abouy 3/8 thick. Ive removed the cabin liner. The cabin top is was built with 1/2 round stringers going accross the top every 2 ft. Can I attach balsa core from inside the cabin.? Will it stick to underside of cabin top if preped properly. Will it stiffen up the cabin top. What do I cover it with. When its all done,Id like to cover with wood strips running fore and aft.
You can attach balsa core from under, but it will be a lot more challenging / labor intensive, and messy. You'll want to review Don Casey's This Old Boat book for information about how to do fiberglass lay-ups upside down.You'll need to grind the fiberglass, wet it out, then apply thickened epoxy to bond the balsa to the cabin top. Then you'll need some kind of a pressure system to hold the balsa firmly in place during the curing period. When it has cured, you'll need to laminate fiberglass to the exposed balsa to protect and seal it.Im' obviously oversimplifying the steps, but this should give you an idea of what's involved.
Building up a lamination of existing fiberglass balsa core and then a new layer of fiberglass will stiffen the existing top. I would check the existing stringers as they might be the source of the weakness that is causing the flexing in the first place. If they are dry and sound then the process you should follow is outlined below.The existing fiberglass surface must be ground to remove any paint or coating that was applied after the glass was originally laid down.Next balsa needs to be cut to fit into the open spaces.For the next steps you have choice of how to do it as overhead lamination is messy and a pain. You could use a vacuum bagging process which will create an absolutely rock solid lamination but does require more equipment and materials. If you are interested in that method West Systems has a good starter guide publication on their website. The straight forward way of doing this is to use thickened epoxy troweled on existing surface with the Balsa wood pressed into the thickened epoxy. You are looking for the epoxy to fill as many of the kerfs ( cut lines in balsa) as possible. Next after the balsa has cured to the top you need to apply fiberglass fabric to the balsa and allow it to extend past balsa core you applied to ground fiberglass. You should extend a minimum of 3" inches beyond the end of the balsa core. This will create a sandwich for the balsa and this is what will stiffen the top. The trick in making this work an not fall down you is as follows.Select a fiberglass fabric that is pretty thick (this helps the fabric stay put once applied) and has a chopped mat back +-45/45 1.5oz mat fabric is what I have used. When applying it you need to make up a thicken epoxy and trowel it on the balsa surface. Then you need to wet out the fabric. Wetting it out requires using enough resin so that it wet but not dripping. Then apply it then quick roll it with a resin roller to remove air bubbles and excess resin.
Adding a layer of balsa core alone will not stiffen your cabin top. You will need to also add an interior layer of fiberglass or plywood to create the "sandwich" effect of a cored deck and the gain stiffness that results from this type of construction.
Hello,yes, it should work. Be sure to prep really well the cabin top and have your material ready with good ventilation. I'd suggest first to pass a coat of epoxy on the cabin top, then wet the balsa core from the fabric side initially with epoxy, then with epoxy mixed with silica powder to catsup consistency. You will then cover with wax paper and adjust a jig to keep the balsa in position between the stringers as the epoxy cures. Then you can finis your work from below by using thickened epoxy.A dry run is essential to avoid making a royal mess!Good luck
This should work-- but won't be easy because you are fighting gravity the whole time. Attach the balsa core to the clean, sanded underside of the cabin using thickened epoxy made by mixing West System type 403 or 406 fillers with the resin. You must now hold the balsa in place, either using the vacuum bag technique or making (ahead of time) a flexible support such as thin plywood or fibreboard and holding that in place with many sticks or pieces of plastic pipe. Put plastic sheet between the balsa and support to keep the support from sticking. After that is cured, remove the supports and epoxy over the balsa a layer (or two?) of fibreglass cloth. You have to depend on the surface tension of the wetted cloth to hold it in place until cured -- kind of iffy, but its been done. You might use staples to hold the cloth in place. This inner layer of glass is needed to make the glass-balsa-glass sandwich into a truss--without the inner layer there is no strength. Get one of the West System books for information on using epoxy and making repairs. Cover the inner layer of glass with whatever decorative surface you like. I assumed you wanted to cover the entire surface with the balsa core, but the West system book describes making stringers out of wood or balsa and glassing them in place to stiffen large panels. This would be simpler and easier. Your solution might be as simple as replacing the original stiffeners with slightly larger pieces of wood carefully epoxied into place.
Yes this will work, make sure you grind fiberglass to get it to adhere properly. Use epoxy not polyester resin. I prefer west system, but most are ok. Glue between all blocks before installing for the best adhesion and stiffness. Use the slowest hardner for the epoxy to get the most time. If you are going to use cosmetic boards under the balsa, and you epoxy them is an well, this will act like an inner skin for the balsa core. Other wise you should use an inner skin of biaxial fiberglass to act as a lower skin and make a complete comosite panel.
As long as you are attaching the balsa to the underside of the actual laminate (not any liner) it should really stiffen up the panel. It's not sufficient to just glue the balsa to the underside however. You need to glass over the balsa with woven roving and epoxy. This creates a sandwich which is where the stiffness comes from. It's a messy job doing that overhead. Thicken the epoxy a little after wetting out with Unthickened epoxy. This will reduce dripping and help the glass stay in place,
You can glue the balsa to the cabin top with thickened epoxy. You will need to make a support system and bottle jacks to hold the balsa in place while the epoxy cures. The. You need to fiberglass over the balsa to keep all moisture out. If it were me, I would just use stiffners between the old ones. Use an instant grab glue then glass those in. Much quicker cleaner job. Hope that helps.
balsa works great when stiffened with an epoxy. I recored my deck with balsa, west system epoxy, and a fairing agent like microballoons. it is messy doing it overhead but can be done. get the west system product guide off there website. another product thats great is the davinicel(sp.?) which adds a lot of stregth for little weight if glassed on. good luck
Hi,I am beginning a repair to the deck and balsa core on my 1983 Cape Dory 22 Sailboat.What is the thickness of the balsa core required?What is the required density?Is the balsa core primed to receive the epoxy resin?Is the West System the preferred epoxy repair system?Thanks,Gary
The thickness will depend on your particular deck architecture, depending on how far along you are with removing the old skin you should be able to discover the thickness just by measuring. If you aren't that far yet (or don't want to cut into the skin too early) you can remove a piece of deck hardware that goes through the deck and measure that way.Any density that is medium or above should be fine. Higher density is probably better.Yes, it will. I had to sand a bit to match some angles and thickness issues (even after sanding the inner skin to what I thought was an even surface), so I decided to give the wood a light sand. But, overall, the epoxy will fill the gaps, and the wood will receive it fine.Yes. I think so. It is purely opinion, but West is very user friendly. I started with little to no knowledge and by the time I was 2 hours in, I didn't need the instructions at all. One tip: buy in large quantities or everything.....save money and save time. Everything from gloves, to mixing/scraping sticks to mixing containers (remember, these are basically one use) to the filler, and especially the epoxy itself. I forget what the largest size for the epoxy and hardener was, but the larger the better.Good luck.
You will have to open the core up first to determine what material was used. Mainly the thickness is the deciding factor. Back in the 80's it was all the same density. The balsa core is not coated, because you want it to soak up which ever resin you use. The prefered resin for any secondary bonding to polyester is epoxy. Polyester resin is great for initial building due to all materials being a primary bond(chemical), but is not so good on secondary bonding. My preference is West System epoxy. Been using it professionally for 14 years and never had a failure or debonding. I also use the 403 filler with it to pack the edges. Get the west system book 002-550 "Fiberglass boat repair & maintenance" It will explain the entire process and options.
Gary,I rpelaced a portion of the balsa core on the deck of my 1989 Searay Weekender 300. West System Epoxy publishes some excellent phamplets on how to repair decks and use their expoxy. I recommend you read it. You can download a copy on-line or go to West Marine or Jamestown Dist. and buy a copy. If you do not have the boat's specifications I think you will have to cut the deck open and measure the existing core's thickness. I know nothing about the density but my guess is you will not have to worry about that. I believe all end grain balsa will have the same density. The West System epoxy was what I used. I followed the directions. I repaired the deck by opening up the top of the deck. Although the repair is technically sound and strong I did not do such a good job on the cosmetics around the cut in the deck. If you can repair it from underneath I would recomment you try that. Good LuckTom
I would buy this again.
It came well packed and was just like the picture.
Easy to use
Exactly what I needed for my '69 14' Pintail deck core
My circa '69 14' Pintail had water saturated end-grain balsa deck core. This was exactly what I needed to replace this and rejuvenate this classic sailboat.
Dan - Pintail 105
Sandwich between two layers do fiberglass, this wood becomes very ridge.
Standard, easy to use
Used to re-core a rotten deck on a J/30. Easy to work with, laminated to backing well, arrived rolled up in a reasonable box and on time for my project.
Excellent Service - Trusted E-Shopping
Pro Balsa is easy to work with.
Easy to use Balsa
I had a small soft spot in the deck around an inspection plate. I had access to remove the bad core and replace it with the new balsa. After epoxying the balsa in place I remounted the inspection plate.
Well worth money
Used it for deck repairs. If you have spongy decks or roof my advise is to do sounding testing with mallet and precisely mark out area that has wet or roten core with marker. Then cut top skin using skil saw and pry out remaining balsa. save top skin. clean/prepare bottom skin. use top skin as template to trase shape on balsa. lay balsa with thikened epoxy prewetting with unthikened epoxy. use west system notched spreader. lay top skin. add weights or drill holes and use butterfly ancors to tie down sandwich. next day grind a recess in top skin. lay 1708 tape . next day sand and do some fairing job. good luck
alex from newton yacht club
Answer to Gary's question
To answer Gary's questions. I used 3/8 thick but 1/2 inch would have been better. It is not primed but that wasn't a problem. I used West systems epoxy and had no problems. Make sure the old core is cleaned out really well so that the epoxy and new core will bond realy well, saturate really well and cover with cloth and it should work great.
Beverly , Ma.
Andrew here is a reply to your question
The product as sold is very adaptable. I use it for various applications, but the absortive nature of the material is very useful for impact test data generation. When qualifying into material systems this is a big plus. For my purposes the standard density works well as I want partial resin take-up. For some structural type work higher densities may be in order. Based on your application you may want to have engineering input. For standard type repairs e,g,. marine, etc. the standard density will suffice. To insert, make a template from light weight plywood or corrugated material and cut to your template outline. If inserting into a cavity bond some 24oz. WORO or canvas fabric to the balsa with a fixative and work into place. Remove the fabric or layup in place. This will keep the balse from flopping about as you set things up.