Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: jaymac on May 01, 2014, 10:04:11 am

Title: S-Boot A Frame repair
Post by: jaymac on May 01, 2014, 10:04:11 am
  Help please what would be the  best way to repair this damage  .I think replacement is a no no  so  which  glue perhaps bearing in mind its locationand vibration . The parts  seem to go back together at the break  Thanks
(http://i152.photobucket.com/albums/s161/jaymac_port/AFramedamage_zps160035b9.jpg) (http://s152.photobucket.com/user/jaymac_port/media/AFramedamage_zps160035b9.jpg.html)
Title: Re: S-Boot A Frame repair
Post by: Tug-Kenny RIP on May 01, 2014, 11:30:24 am

I would use epoxy resin and fit a long narrow screw down through from the inside.

Ken

Title: Re: S-Boot A Frame repair
Post by: derekwarner on May 01, 2014, 11:46:30 am
jaymac........along similar lines to Ken......is this a triple prop?........how many A frames are sheared?....... some major surgery may be required in the stern deck area for access

1. assemble the sheared A frame assemblies to the hull
2. lightly tack weld each joint back together with a Superglue
3. select a reinforcement size brass dowels.........1/16".....1/8"..?
3. drill down into each arm of each A frame component with the respective size for size of the dowel
4. spiral flute the trimmed dowels & insert with a compatible epoxy glue
5. after the curing, gouge the external joint fracture area in each leg & repair with the appropriate fillers etc   :-))

Derek


Title: Re: S-Boot A Frame repair
Post by: jaymac on May 01, 2014, 11:58:46 am
 Thanks both    and just  two frames/ props both sheared Derek methinks  just gluing is about my max skill  I don think there is enough meat use  a screw  there appears to be a bit of metal wire showing  which may have been some kind of pin . If  I could get hold of the italeri build manual it might show if they are pre or post attached to the hull  the deck I believe is removable(screws)
Thanks again
Jay
Title: Re: S-Boot A Frame repair
Post by: RAAArtyGunner on May 01, 2014, 12:58:46 pm
Jay,
 
Yes the deck should be attached with screws supplied in the kit.
 
The "A" frames from memory are attached by 'plastic' pin extensions.
 
Title: Re: S-Boot A Frame repair
Post by: jaymac on May 01, 2014, 01:02:44 pm
Thanks Raaarty   thats where they broke off it seems bloody parcel force
Jay
Title: Re: S-Boot A Frame repair
Post by: RAAArtyGunner on May 01, 2014, 01:17:54 pm
Your welcome, O0 O0
 
It should be possible to glue them back, the plastic pins can be replaced with metal such as brass railing etc
 
Another 'trick' is to melt some of the kit plastic with glue to make a putty and spread it around the join it will reinforce and help glue them in place.
 
One of the guys building plastic "tank' kits may have more detail on how it is done. The 'putty can also be used as a filler and will harden as part of the section it is applied to and can be sanded etc.
 
Good luck.
Title: Re: S-Boot A Frame repair
Post by: jaymac on May 01, 2014, 07:09:15 pm
 Thanks
Jay
Title: Re: S-Boot A Frame repair
Post by: jaymac on May 02, 2014, 07:31:17 pm
OK got the deck offf and  now can see from beneath any drilling/pinning is a no no for me so which would  the best glue be     easily obtainable brand    just epoxy means squat to me
Title: Re: S-Boot A Frame repair
Post by: eddiesolo on May 02, 2014, 07:59:34 pm
If brass pinning and drilling is not what you are up to, and nothing wrong with that, then I would suggest if the part fixed to the lower hull is hollow and the part that is broken hollow then a either: a plastic lollipop stick, or other small round rod instead of a brass rod. As for epoxy, you want a two part epoxy, get a good quality one. Mix up and then with the hull upside down add the epoxy into the broken hollow section, insert the rod (this is for added strength) then you need to add epoxy to the broken lower part and seal together, try and not get any air-bubbles as this will add weak areas. Wipe around the broken seam to make sure that the epoxy seals the area good. Leave to dry for 48 hrs so that it is well cured before lightly sanding the epoxy to shape-shouldn't need much just to tidy up prior to painting-use masking tape to mask off the hull, props etc just leaving the A-frame-now use a good primer and spray lightly-once cured 24hrs, touch up with paint. Make sure the A-frame is aligned correctly prior to fixing.


Si:)
Title: Re: S-Boot A Frame repair
Post by: jaymac on May 02, 2014, 08:05:50 pm
Thanks but they are solid
Title: Re: S-Boot A Frame repair
Post by: Neil on May 02, 2014, 09:47:45 pm
if they are the same plastic as the hull, then simple plastiweld liquid poli glue will "weld" them together. neil.
Title: Re: S-Boot A Frame repair
Post by: RAAArtyGunner on May 02, 2014, 10:16:15 pm
if they are the same plastic as the hull, then simple plastiweld liquid poli glue will "weld" them together. neil.

Plastiweld is a plastic cement which the instructions say to use under useful advice
Title: Re: S-Boot A Frame repair
Post by: jaymac on May 02, 2014, 10:31:45 pm
Thanks guys    dont know if the same plastic  but  would think probably .Raarty did you you have to Glue the Aframe as well as  the pins
Also is plasti weld  available under other names
Thanks
Title: Re: S-Boot A Frame repair
Post by: RAAArtyGunner on May 02, 2014, 10:32:56 pm
Try this one,
 
 
Title: Re: S-Boot A Frame repair
Post by: RAAArtyGunner on May 02, 2014, 10:41:06 pm
Thanks guys    dont know if the same plastic  but  would think probably .Raarty did you you have to Glue the Aframe as well as  the pins
Also is plasti weld  available under other names
Thanks

There is a member here, local to you, Star Loc adhesives who has Plastic cements. Polystyrene glue is a plastic cement and made by Revel and Testors.
 
Yes, you glue the entire item the pins are only for locating the item and in my opinion shear off due to their design the 'glued base' is the strength.
 
Plastic cement literally melts the two surfaces together that is why they say don't use too much as it will dissolve the plastic, AKA polystyrene. This is the realm of plastic kit making which our Resident Tamiya tank poster is well versed.
Title: Re: S-Boot A Frame repair
Post by: RAAArtyGunner on May 02, 2014, 10:43:45 pm
 
Here is the link to his tank thread, a personal message would get you some local assitance
 
http://www.modelboatmayhem.co.uk/forum/index.php/topic,47300.msg478772/topicseen.html#msg478772 (http://www.modelboatmayhem.co.uk/forum/index.php/topic,47300.msg478772/topicseen.html#msg478772)
Title: Re: S-Boot A Frame repair
Post by: eddiesolo on May 02, 2014, 11:09:04 pm

Here is the link to his tank thread, a personal message would get you some local assitance
 
http://www.modelboatmayhem.co.uk/forum/index.php/topic,47300.msg478772/topicseen.html#msg478772 (http://www.modelboatmayhem.co.uk/forum/index.php/topic,47300.msg478772/topicseen.html#msg478772)


I'm here... :-)


Right, so we have a 1/35 scale S-boat with broken A-frames. As you cannot drill and pin then option I would use is CA glue (Cyanoacrylate) a thin variety, they do a medium and thick but they maybe too thick. Get a good quality one.


Clean the area of the break and just around the edges so you get a good clean bond-the thinner the glue you will get more capillary action as it runs into the joins. A good tip is one the area has set, you can lightly score around the original break, not too much and then mix some of the CA glue with baking powder/soda (sodium bicarbonate) the glue and the powder mix makes a super and very strong filler, apply in the the grove and then just lightly sand to shape-touch up with paint.


The advantages of using a good quality CA glue are that it bonds better and is also water resistant.


Si:)
Title: Re: S-Boot A Frame repair
Post by: vnkiwi on May 03, 2014, 01:01:41 am
Sorry to disagree Eddie,
but a solvent weld using Plasticweld for Polystyrene, (assuming the plastic is polystyrene) when done properly will have the same strength as the parent plastic.
CA is only as strong as the bond it has to the plastic, which in most cases will be less than the strength of the plastic.
I do a lot of 3D printing using ABS, and the only "glue" I use is Acetone, and buy it in 500ml containers, for less than the price of a tube of "plastiweld"
I apply it with a toothpick or a small clean brush. Put the parts together, apply the brush(charged with acetone), and the solvent wicks in. Keep the parts clamped together, so there is some pressure to keep the two faces together and 48 hours later you have virtually one part again.
My recomendation would be the same as RAAArtyGunner, use "plastiweld or some other SOLVENT plastic "glue" which are formulated for the type of Styrene used in plastic kitsets.
Hope this is of some help
cheers
vnkiwi  :-))
Title: Re: S-Boot A Frame repair
Post by: eddiesolo on May 03, 2014, 09:58:12 am
Sorry to disagree Eddie,
but a solvent weld using Plasticweld for Polystyrene, (assuming the plastic is polystyrene) when done properly will have the same strength as the parent plastic.
CA is only as strong as the bond it has to the plastic, which in most cases will be less than the strength of the plastic.
I do a lot of 3D printing using ABS, and the only "glue" I use is Acetone, and buy it in 500ml containers, for less than the price of a tube of "plastiweld"
I apply it with a toothpick or a small clean brush. Put the parts together, apply the brush(charged with acetone), and the solvent wicks in. Keep the parts clamped together, so there is some pressure to keep the two faces together and 48 hours later you have virtually one part again.
My recomendation would be the same as RAAArtyGunner, use "plastiweld or some other SOLVENT plastic "glue" which are formulated for the type of Styrene used in plastic kitsets.
Hope this is of some help
cheers
vnkiwi  :-))


As this boat is going on water (I think) then the use of CA using also a CA filler, in my mind, seemed the best option. However, having read your post and had a good think you are correct-I have used Acetone in builds and to be honest you have to get it right or you can make a mess-so this maybe not be the best option, in this case. As for plastic weld, either liquid or two part epoxy would/should do the job. One thing I would be tempted is to cut down a sliver of plastic from an old box or carton and glue that into the hollow areas just give more strength.


Si:)
Title: Re: S-Boot A Frame repair
Post by: jaymac on May 03, 2014, 12:47:46 pm
 Thanks againguys  yes Eddie she is going on the water . There are  no Hollows to fillin just rough surface where it sheared .I will porobably give the plast weld ago.Am toying with a slip of  thin brass strip or plasticard on the inside glued on the inside of the legs . Nice tank  never saw one in that condition in my day not even the centurions  :}
Jay
Title: Re: S-Boot A Frame repair
Post by: jaymac on May 03, 2014, 01:00:07 pm
This any good  or any  below it  looking at maybe getting something local
http://www.amazon.co.uk/Devcon-Plastic-Welder-Syringe-G-S220/dp/B004RNWA0Y/ref=wl_mb_wl_huc_mrai_2_dp#productDetails (http://www.amazon.co.uk/Devcon-Plastic-Welder-Syringe-G-S220/dp/B004RNWA0Y/ref=wl_mb_wl_huc_mrai_2_dp#productDetails)
Title: Re: S-Boot A Frame repair
Post by: Stavros on May 03, 2014, 01:19:34 pm
go to your local builders merchant and get some plastic pipe  cleaner the LIQUID  one NOT  the adhesive same stuff as plastic weld use a small modeling paint brush or cocktail stick tins are around 250ml wil last a lot longer and you cant knock it over likr the small bottles


Dave
Title: Re: S-Boot A Frame repair
Post by: jaymac on May 15, 2014, 07:08:24 pm
Well Plastic weld  no work   one came apart  without being near the water   Done again both came off in the water . I thought perhaps  the shafts might be slightly warped puttting  to much strain   .Though that might well be the case Plastic weld would not even hold the centre rudder together and thats  two vertical leafs with no stress Back to the drawing board
Title: Re: S-Boot A Frame repair
Post by: shadysadie on May 17, 2014, 08:22:32 pm
Extreme surgery, I know, but could you not fit a pair of brass A frames from the likes of George Sitek? Once correctly lined up and epoxied into position the whole assembly would be very strong and very unlikely to give any future problems.

David.
Title: Re: S-Boot A Frame repair
Post by: jaymac on May 17, 2014, 10:31:40 pm
Many thanks David for the link  If push comes to shove may consider that though doubt I would be able to work out what s needed
Thanks
Jay
 
Title: Re: S-Boot A Frame repair
Post by: Andy_k on May 18, 2014, 05:50:05 am
heres another option epoxy putty drill 2 small holes either side off the broken parts mix some putty position the parts together and mould the putty around the brake pushing the putty into the holes when it cures it can be filed to shape
the finish will be slightly thicker than the original part but also stronger just remove paint and roughen area around break as well as the holes  :-))




 http://www.ebay.co.uk/itm/Waterproof-Epoxy-Putty-Repair-Adhesive-Seals-Leaks-Pipes-fix-and-fill-holes-/321395086382?pt=UK_Crafts_Cardmaking_Scrapbooking_Glue_Tape_EH&hash=item4ad4a3d42e
Title: Re: S-Boot A Frame repair
Post by: longshanks on May 18, 2014, 09:16:39 am
Hi Guys

Just been out and measured the A frame in question. Each plastic leg is 9.5 x 2mm and come away from the hull at an angle.

As already stated for static display plasweld is more than man enough!

To use this in the water with a prop and shaft turning at 6 - 16000 rpm !

With a prop and shaft  that are not perfectly balanced or worse bent !

Add to that the probability of hitting a twig in the water and the stresses invlved !

Get real ! This is a plastic kit made for static display. The only realistic chance is to make brass A frames, properly lined up with 'straight' shaft. The A frames should have tabs on the inside fixed to reinforcement.

Sorry to be the bearer of bad news but in my opinion anything else is only  going to involve more wasted time/money and heartache !

longshanks