Kit 6 - Tyres

ModelWorks 4 inch Scale Burrell Agricultural Traction Engine
Kit 6 arrived Tuesday 30 March
 

 Tuesday 30 March: Today kit 6 arrived complete with chimney.  I doubt If I will attempt the wheels until the weekend but the chimney looks a nice clean job.

Thursday 1 April: Today I completed the chimney.  To tighten the nuts down the chimney I used a ratchet on the end of a stick.   There was enough movement to get at least one "click" on the ratchet.

I attached the stick with masking tape so that it formed a flexible joint. This enabled the ratchet to be pushed from side to side without the stick hitting the chimney.

The completed chimney attached to the smoke box.

So far I have I have dry fitted one front tyre. It was a bit of a struggle because without the adhesive it would not slide. I plan to fit all the tyres Saturday.

Saturday:  I decided to fit  the tyres in the garage. ModelWorks supply Isoflex Special Primer and Isoflex High Performance Liquid Rubber to bond the tyres to the rim.  The instructions warn that this is going to be messy and it lived up to expectations.  Thoughtfully ModelWorks supplied 6 pairs of above average disposable gloves. Even though I wore surgical gloves under these I managed to get a little goo on my hands and wrist.  I was pleased to discover that Acetone (Nail varnish remover) soaked on a tissue removed the marks. I also use Acetone to clean the brush.

I found that a rag soaked in paraffin was useful to wipe my gloved hands and tyre levers to avoid things getting too sticky. The paraffin did not dissolve the liquid rubber but it seemed to enable it to slide from tool to rag.  I didn't try try petrol as I didn't have any! 

I made the mistake of leaving the final positioning of the tyres until I fitted the last one.  I found I could not move the front tyres which I fitted first.  Luckily I had positioned them about right and will have to do.  Looking on the bright side, the Isoflex has got a firm hold and hopefully nothing is going to shift the tyres.

August 2007: Update Many constructors have lost one or more tyres whilst cornering on tarmac.  I have sought advice from the Model Engineering community and Isoflex is regarded as one of the better methods of home fixing.  Vulcanising would be the perfect solution but this is expensive and should be performed before the tyre is painted.

The bond seems to fails between the Isoflex and the tyre so I recommend paying practical attention to preparing the inside of the tyre.  I suspect there may be traces of silicon release agent left over from the mould and I would be inclined to remove the surface layer of rubber using a power tool if necessary.  If this left a rough surface so much the better.

See my notes here and here

Disaster Despite taking the precaution of putting the butt joint on the opposite side to where I was using the tyre levers the but joint on one of the front tyres has split.  While the top of the joint is intact the bottom is split open for a considerable depth into the tyre, probably all the way through as there is a small crack on the far side.  I not sure what I am going to do but my instincts tell me that it will eventually need attention. I plan to contact ModelWorks for advice.

Sunday: I decided to fill the crack with a little liquid rubber.  In the enlarged close up below It does not look too pretty. I think when the goo has set I will be able to dress the joint so that it looks fine however will the join hold up?

I tried to form a neat radius where tyre meets the rim and thus far I am not satisfied with the results. It may be a job for a finger.

All done; time to think about painting.

Below are pictures I took at ModelWorks or "How it should be done!"