Hello,

I know this has been asked before but could not find the answer. Can anybody give me an estimate of how much epoxy, flour, microbeads etc needed for a kit build? I have worked with both MAS and West systems and much preferred the MAS but was a clear finish. Any preferences for this boat. Now for the really stupid question. Never painted a wooden boat before. Is the paint epoxy paint or regular epoxy with pigment added?

Thanks,

Dan

Hi Dan-

Both MAS and West Systems are good epoxies. I personally prefer the Marine Epoxy that Chuck Leinweber sells at Duckworks, www.duckworksboatsupply.com and have used it on several boats, including the Red Scamp.

On the Red Scamp, which was from plans, I used at least 9 gallons of epoxy. I used (or bought) 5 # of wood flour, I don't use microballoons.

Just use ordinary marine paint and undercoater to paint with. Don't use epoxy with color pigments added. I used the John Welsford method of painting he recommends, enamel undercoater and porch and deck floor enamels, all oil based.

Mike Monies- the Red Scamp

Thanks Mike. I'll check out the Duckworks site. How wide do the filets need to be? Thinking as much of weight savings as cost.

Dan

Dan,

Use of epoxy and fillers, as to quantities, will vary greatly between builders. Beginning builders tend to use more than necessary in many cases.

Mike seems to have used wood flour almost exclusively while others use flour & other fillers. Also different epoxy manufacturers favor different combinations.
Mike's build called for a lot of lamination as he used thinner sheets of ply and built up to desired thickness. That eats up the epoxy. That being said, we gave all wood three coats of epoxy while he used a lot of paint where we used epoxy

This is what we (SCA) recommend as a good estimate for kit builders. Any other kit builders out there that have finished up or about finished, please chime in with your experiences with SCAMP.

For the kit build a good starting point might be:

6 gallons of mixed epoxy
1 gallon (volume) of wood flour
5 quarts (volume) low density microballoons
5 quarts (volume) colloidal silica
10 yards 6 ounce "E-type" fiberglass cloth (38"-50" wide)
30 yards 9 ounce biaxial fiberglass tape (4" wide) or 6 ounce/2" wide

Fillets: There are structural fillets that are sometimes beefier, and then there are fillets to fill in a joint (think 90 degree joint) with a concave filler so that wetted-out fiberglass cloth will lay in smoothly without lifting away from the surface.

Fillets in general really eat up the epoxy!

I hope this helps.

Simeon

In my reading of the tips for building JWs boats as per his website, it appears to me that he recommends stitch and glue (fillets) over taped on the inside and standard epoxy and tape on the outside of the joint.
I understood that he then recommended painting with oil based enamel.
I will not be using the kit, but am working from plans.
In the case of Scamp, it appeared to me that he recommended covering the bottom with a layer of epoxy/glass and running it up to the top of garboard plank lap. He also recommended epoxy/glass for the cuddy roof.

I will recheck my plans to see if the entire hull was specified to be epoxy coated.

Please correct any misconceptions I may have here.

Early this morning while I was half asleep, Mike explained he used a different method of build on the Red Scamp , no fillets, as he used wooden doublers on his joints. He said this is a lot more effort and work and isn't appropriate for the kits! Filleting is correct for the kit boats.

Mike recommended reading the West System Grudgeon Brothers book on epoxy, their method for making fillets and applicators for them.

If he were building another Scamp he would probably do what the school did in its build as far as coating each piece of plywood with epoxy. I say that because the last boat he has been building has done that and he likes the treated plywood. On the Red Scamp he did it John Welsford's way, with glass cloth and epoxy across bottom and up sides to water lines, then painted it with enamel and undercoater, oil based.

On the second Scamp he put epoxy up hull sides after it was built. If he were doing a third one (something I would not rule out!) I think he would coat every piece of the plywood before he built the boat!

He also would not laminate wood I think and use appropriate thickness of plywood. We are back to using marine ply even though we are driving to Houston, TX to obtain it.

Jackie Monies (for Mike)

I also had some questions related to epoxy coating. On the sheet 3 of the plans the garboard plank to hull bottom and plank-to-plank joints are clearly marked "fillet and glass tape". The areas of question for me are the areas marked "fillet". This is marked on the areas between the taped plank-to-plank joints, faces of the longitudinals, bulkheads, etc. that are inside the floatation chambers and seat storage lockers. My guess is that in this case "fillet" means to epoxy coat (no fillers) these areas. It could also be a generic term for sealing the wood in these areas with epoxy or paint. What is the correct answer?

Tony
SCAMP 98
League City, TX

Phil,

There is a difference between "epoxy coated" and "epoxy/glass" or "fiberglass coated".

The wood is epoxy coated to seal the grain of the wood to prevent moisture penetrating. We recommend 2 to 3 coats to make sure no area is missed or epoxy applied too sparingly. A good coating of oil based paint per Welsford/Monies' suggestion has the same effect. We had 3 coats over the entire boat, then painted where desired.

On the kit, or built from plans, we recommend covering the bottom of the hull and up to the top the first plank (garboard) lap joint with 6 oz fiberglass. On my personal SCAMP build I intend to also cover the outside of the vulnerable bow and stern transoms (B-1 & B-8).

I hope this helps.

Simeon

The other large area to be covered with fiberglass cloth is the cabin top.

The lower plank #1 (garboard) is glued to the hull bottom panel. Stitches are used to facilitate the process because of the torsion, especially in the bow area. Fewer stitches are needed for planks 2 & 3.

A fillet is then laid on the inside joint and the fiberglass tape applied over it. There is no need to tape the outside of the hull at the joints. Outside the hull, the joints between planks are filleted. We waited until after we turned the hull botton side up to do these fillets because it is much easier.

We recommend coating the entire boat with epoxy to seal it, but only those exterior areas with fiberglass.

I hope that is clear.

Tony:

As to your confusion regarding the sheet 3 items mentioned. The areas marked "fillet" definitely need epoxy thickened with fillers. Mike's recommendation about reading the West System Grudgeon Brothers book on epoxy and their method for making fillets is an excellent comment. To attempt to fillet with only epoxy just won't work as the epoxy just flows in an attempt to self-level.

These fillets are there to provide structural support for the joint. Where it is indicated to "fillet and glass tape", the fillets are of the same composition as the other ones. The glass tape is then laid over the fillet and epoxied in place. This provides additional structural strength. The fillets here also permit the tape to lay smoothly in the joint without lifting because of air bubbles and/or tension.

The joint area between the bow & stern transoms (B-1 & B-8) and the hull bottom and planks 1 - 3, should also receive the "fillet & tape" treatment.

I hope that helps to clear things up.

Simeon

Simeon,

Thanks for the reply. Unfortunately, as I feared my question would be misunderstood so your reply did not answer my question BUT your pictures did. A bit of misinterpretation of the plans on my part. I come from a background of aviation/marine vacuum bagged foam core stressed skin construction where we would never just fillet a join between two panels. The fillets would always be reinforced with a layup schedule similar to the skins (since the strength is in the skins not the core). In this case the strength is obviously in the plywood/core and the bonding area with fillets is sufficient to adhere the pieces together and meet the expected working loads. In your pictures, I see that the bulkheads and longitudinals have only fillets (no tape) between them and the hull bottom, planks, deck, etc. The fillets WITH tape are being used where there is limited contact area between components and the expected operating loads and load paths require reinforcement of the joint.

I'll ask another question so my misunderstanding will not have been a waste of time for other builders. Are the fillets (not the taped joints) made with wood flour thickened epoxy or are others using microfibers (or West System Filleting Blend) for the additional strength these fillers provide? The wood flour and cabosil fillets are definitely easier to apply and result in a smoother surface less likely to require significant sanding prior to top coating with paint or the like.

Best Regards,
Tony
SCAMP 98

Great comments. I looked into the Marine epoxy from Duckworks. Looks to be about half the price of West or MAS. Does it seem to do the same job? Do the cheaper epoxies penetrate less well or finish less well? How is it for a clear finish - ie if wood showing. If not clear, is there a problem using the cheaper epoxy for the coating, fillets, bonding and fiberglassing; then using something like MAS for anywhere a clear finsih is wanted?

Thanks,

Dan