Pay'nPak Contruction Instructions

Some things you will need

To finish the model you will need a few things. The list below is not exhaustive but will get you going

• a sharp utility knife
• A flat building board - I use a chipboard shelf piece.
• Sanding block - medium and fine.
• Model standard fast and medium and slow CA glue.
• Square.
• Cling film.
• Sealer, spray paint.
• Brushes.

General notes

• Please read through the instructions before starting assembly. The kit contains the parts as shown below, two balsa stringers and an ABS moulded cowling.
• Covering the building board with cling film will help to prevent superglue sticking parts to the board.
• This boat is supplied as it was fitted with a turbine, the same hull was used with an internal combustion engine but with the cab at the rear and narrow wing supports. You can build this but wou will have to scratch build the cowl. A version of this boat was also run by Atlas Van Lines and that will give an alternative colour scheme.
• The boat described in the plans is the final version of this boat. In the original the tunnel was streaight across the boat. On the first run the boat somersaulted and was damaged. It was rebuilt but this time with the extended central nose. This nose actually provided a central mounting for two small wings either side of it . The wing angle count be controlled from the cockpit in order to give it some stability control. Whilst racing in Seattle? another boat was flung in front of PaynPak which ran over it and flipped.

Instructions

1. Using a utility knife carefully cut the side stringers (top right) from their carriers, line them up on the baseboard and glue them together using medium CA to give time to relocate if necessary. Make sure that they are together in the correct location. You can pin them in position and tack with superglue. After tacking remove from the board and run thin CA in to the join.
2. Remove the formers from their carriers and test fit to the stringers. The slots may need slight adjustment to provide the best fit. Where pieces will be sanded the largest edges are the "fit edge".
3. Once you are satisfied with the fit stand the assembly on the build board ensuring that both stringers etc have the same touch points. Check that the formers are at right angles to the stringers and tack in place. Check the assembly and glue firmly at all contact points by running thin CA into the joints and holding until set (watch your fingers).


4. The two long pieces (bottom right) fit into the side tunnels, hard up against the stringers and overhanging the transom by 1/16th inch (sheeting thickness). You will have a gap on the inboard side - do not worry about this. Line these up, check the hull for true, tack and then glue in place with CA. Run CA down the seams to seal the joints.
5. Take two of the hooked shaped pieces and laminate together as accurately as possible. Medium CA will give a little movement time or thick CA will give you about 10 seconds. Do this with the other pair as well - you should now have two thick hooks. These hooks form the tunnel side walls and the flat section glues to the outside of the tunnel bases and the tunnel sides on the frames. The hook overlaps the base.
6. The shaped leading edge needs to be cut to fit across the front of the hooks and across the side tunnels. The side tunnel pieces have their bottoms flush with the side tunnel bottoms bottom.
7. Fit the top ¼" square stringers.
8. Check the assembly is still straight and keep checking through the build. Up to gluing the deck on you can remove twist by ensuring everything is flat on the building board before gluing. i.e. same contact points!
9. The rear centre tunnel base can now be fitted. It should slide in between the side tunnels at the rear and come up and over the side walls centrally. The side walls will need sanding carefully at the rear to provide a smooth transition. You may need slight adjustment to get the fit absolutely correct. Small gaps can be filled later.
10. The front centre tunnel pieces can now be fitted with the grain going across the tunnel - to allow them to bend to shape.
11. Fit the internal sponson doubler on the right hand sponson (from the rear).
12. Sand the sponson frames so that their edges will fall parallel to the sheeting when it is fitted. Test fit the sponson side walls (RHS bottom blue parts), the inner edges must touch the limits of the frames, when happy tack and glue in place. Sand the bottom edge to fit the sponson bottom for step 12.
    
13. Line up the sponson bottoms and mark where the side step should be (approx 1.6 inches or 42mm). Cut a parallel slit in them for 5.5 inches from the rear towards the front. You have a little leeway but measure thrice cut once! Line them up - check the hull for twist, tack and glue in place
14. Sheet the top of the nose with scrap balsa across the grain. Glue the 1/16th ply transom doubler in place.
15. Check the hull for twist, if it is twisted then block it up with weights to take the twist out and seal the inside with 3 coats of G4 sealer (from BONDA) or thinned epoxy (G4 is best as it is re-coat dry in 1 hour.)
16. You can pack the sponsons with foam at this point for boyancy... just in case!
17. This is you last chance to remove twist - after this it is set in for good. Make sure there is no twist introduced whilst you do this. Align the outer deck wing pieces and glue the outer decks together. Glue the inner deck pieces to the sides of the outer pieces but only up to frame D position. From there they split and the inner deck follows the centre section which is lower. Sand the top of the frames so that the deck fits. Once you are happy with the fit glue it all in place with thick CA. Fit the front inner deck panels. Because of the deck curve the rear of these will need trimming to fit.
18. Fit the rear deck pieces from Scrap Balsa laid cross grain.
19. Fit the rear anti trip panels (mid RHS of the drawing top blue parts). You will need to sand the edges to fit. Fit the outer right transom doubler and glue in place.
20. Sand and fill the assembly. Seal with 3 coats of G4 (it grain fills so don't worry) allow to set after the first coat and sand the raised grain off and fill any holes.
21. Remove the centre sections of frames C,D and E, you can do F and G, and Seal the inside tops of the deck in the equipment bay that has been created.


22. Glue the two halves of the fins and wing together and sand to shape. Sand the bottom of the wings so that they contact the hull and do the same to the ends of the wing. Make sure you get it all at the right angles and tack in place. When you are happy run glue ito the joins.
23. Fitting the cowl is a bit tricky. We suggest that you treat the cowl as two parts - the front section which will be fixed and a rear section that will be removable. We suggest the break point should be somewhere around former C. Mark and cut through the Cowl at this point. Mark out and trim the rear section to fit.
24. Trim the remaining front section, use scrap balsa to pad out the fitting and if necessary for the side sections. This may be necessary as the body will have moved from optimum during build due to built up stresses.
25. I actually set mine in place using car body filler, It would not be a bad idea to fill the front of the nose with expanding foam but do it slowly and leave for a good while for it to expand. You don't want the boat blowing out
26. Seal any remaining sections of the boat, sand the cowl parts to remove the gloss and provide a key. Paint with Automotive acrylics and apply a final laquer coat once satisfied.
    
    
    I bought my declas from decals from here

Since finishing the prototype a couple of small things have come up.

1. It is not mentioned above but you do have an option of sheeting the boattom of the sponsons with thin ply. If you do this use 0.8mm ply, trim it to the exact size and glue it to the bare wood of the sponson bottom with a film of medium or thick Cyano acrylate
2. I removed the centre of the rear formers in order to fit the hardware and then found it a bit of a problem to get the nuts on. Eventually I bolted from the inside using a long hex key in an allen bolt with a slip of paper in the head to retain it. It was still hardwork. You could easily put a hatch in here but ideally you need to do that at an erlier stage of the build.
3. My 4S 5000 Lipo cell arrived and it is just too narrow to fit the well. I have landed up removing material intenally after the Cab was attached - really hard work. So check your cells fit before you fit the cab and carve out the necessary and seal first!
4. Having now got all the hardware in the bot it has become apparent just how much room there is so If I built this again I would put foam in the sponsonas and all the other spare places that I could
5. I believe now that the plans are a bit of a mix. The nose detail is correct for the piston engine rear seat version but should run straight across for the Turbine version.... not sure as there are very few pictures but the info does indicate that the turbine hull was modified to start with
6. I ran the boat and put it up a tree - luckily before the decals went on - so it is now repaired and with decals. It has a tendency to submarine if you start up slowy but gets up and goes really well if you just nail the throttle.
7. Fixed the boat and ran at the Weymouth International Model Boat Festival, ran well on a 37.5 swapped for a 40.5 and the back end was bouncing, it was fast but needs some weight in the rear. Chris Osman took some photos and hope to get them shortly